Green Lantern scans an area finding an underground compound. He again shows his phasing power and turns a battering ring into a stream of water. Also possibly a reference to the Golden Age Green Lantern being unable to affect wood instead of yellow
So those are the founding Justice League Members using just the feats in their first issues. As general statlines:
Superman, Wonder Woman, Aquaman, and the Flash are wall level physically. Batman is upper human level while Martian Manhunter and Green Lantern both lack physical feats but might be superhuman in durability just from enduring high speed movement with both having much higher attack potency due to Martian Manhunter's eye beams and Green Lantern's energy constructs.
Batman is upper human tier speed physically. The rest are superhuman to some regard with Superman, Aquaman's swim speed and Green Lantern's flight speed being subsonic. The Flash is the speedster at confirmed supersonic speeds with one highball interpretation at relativistic to faster than light. However Wonder Woman and Green Lantern can both react to bullets after they are fired and Aquaman has an odd feat of pushing a boat out of the way of a bullet, but it's not known he started to push it, so it might just be dramatic timing that he pushed it out of the way at the last second.
Beyond this Batman and Wonder Woman both have combat skill feats and all of them demonstrates at least some level of above average intelligence.
I wanna start by comparing the characters whose powers are mostly just their enhanced stats: Superman, Wonder Woman, Aquaman, and to a lesser extent The Flash.
Comparing them in terms of raw strength and durability:
Superman in terms of raw strength is able to leap a tall building in a single bound. A calc made
here suggests a figure of 96 Kilojoules. The source uses a mass of 101 kilograms which if is real comes from outside the issue. Using more standard masses of 70-75 kilograms for an adult man gives between 67 Kilojoules and 71 Kilojoules. It's also stated that nothing less then a bursting shell can stop him, but such is a relatively vague statement that while probably impressive is hard to quantify.
Wonder Woman is stated to be 100 times the strength of the best athletes. The world record for is 1008 joules thought this was substantially after the story was written. Still, professional heavyweight boxers can very often reach 700 joules in their punches so somewhere between 70 Kilojoules and 100 Kilojoules would be roughly Wonder Woman's level at this point
Aquaman's feats seem a bit more contradictory in that he is able to survive the pressure of deep underwater which the story makes a big deal of but is knocked out by a hammer dropped on his head. The two possibilities are either that he is much less durable when surprised or that he is specifically weaker outside the water. This is true for Aquaman in general, but isn't stated in the story though might arguably be implied by him being a human that "lives and thrives in the water." His feat of surviving the pressure of the deep ocean is hard to assess as it's not stated how deep he is, only that he has "tons of water pressure on all sides" The story does say he falls into an extinct undersea volcano. Undersea volcanos typically range from being hundreds of meters deep to several kilometers deep. Every ten meters you go underwater increases the pressure by one atmosphere so using 200 meters for the shallowest of undersea volcanos, it should be 21 times the pressure of surface level. The pressure of atmosphere is just over 0.1 joules per cubic centimeter. 21 times that would be 2.1 joules per cubic centimeter. Using the same 70-75 kilogram measure for an adult American male suggests a volume of 70,000-75,000 cubic centimeters gives a value of 147 Kilojoules to 157.5 Kilojoules for his whole body durability. This number is lowballed from using the shallowest possible depth, though also is the durability of his whole body at once not accounting for the focusing effect of something like a strike. For comparison the human surface area is about 18,000 square centimeters, while a fist, the amount of energy that would receive a punch is about 50 square centimeters.
The Flash's feat is more simple, he plows into a brick wall like a gigantic drill. Using average male height of 1.7 meters tall we can estimate the indent as similarly tall. The width is not quite the same and the depth he penetrated into the wall is not clear, though evidentially the wall didn't collapse. Assuming he indented his whole body into the wall it would be indenting the same 70,000-75,000 cubic centimeters into the brick wall with red brick having a violent fragmentation value of 2.81-5.56 joules per cubic centimeter giving a range of 196.7 kilojoules to 423.75 kilojoules. That said this is once again the energy of his entire body, with the incident knocking him out temporarily.
For Speed Comparison:
Superman's speed was given by the earlier calculations as between 27 and 50 meters per second from being faster than a locomotive as well as calculating the speed of propulsion of his legs during his jump as 46 meters per second however this uses his height not given in this issue specifically, using the 1.7 meters figure. Keeping everything else the same would give a speed of 42 meters per second.
Wonder Woman outpaces a deer with most deer reaching speeds of roughly 15-18 meters per second which would be her leg speed. Mala shoots at Diana five times at what the narration describes as "point blank" which the pictures depicts as being several meters away. The nature of the guns are unspecified but the comic notes how the Amazons have more advanced technology than man's world, 1940's small arm fire regularly exceeding 250 meters per second. A quick estimate put the distance at 3.55 meters, meaning the timeframe is 0.0142 seconds. Assuming Mala shot somewhere near Diana's shoulder as Diana did to Mala and she had to move her bracelet to block it that suggested Diana had to move her bracelet roughly the span of her arm which on average for women is 61-66 centimeters giving speeds of roughly 42-45 meters per second
For Aquaman he is stated to swim faster then any racing craft would have included speedboats with speedboats regularly reaching speeds of of 52 meters per second. He has other speed feats but this is the fastest.
Finally, the Flash is the simplest. He explicitly can break the sound barrier and regularly does. He is also said to keep increasing in speed after doing so, and the original caption describes him outracing his shadow. This would be somewhat inconsistent though with bullets still noticeably moving to the Flash.
Comparing the four how do I think they do?
Well I think if Aquaman's inconsistent showings are based even this early on him being in vs out of water, then since the fight would probably take place outside of water, the other three would win. That does kinda seem unfair to him since all his powers in the first issue revolve around water but on the other hand putting it in the water is unfair for him as it's a specific battlefield he is at the strongest and the other three would be hampered in the movements. Inside of water he might be the strongest. His speed feat is faster than either Superman's or Wonder Woman's, and there's no suggestion that underwater Flash can swim at the same speed as he can run, though an interesting fight might be Aquaman in the water with Flash running atop it.
Comparing the others, Superman can run roughly 2-3 times the speed of Wonder Woman but her reaction/attack speed seems easily enough to react and tag him. The Flash is substantially faster than both, by several times over. That said the Flash would basically have to ram either Superman or Wonder Woman with his whole body to try and directly harm him or they would just tank his blows, and the knockback force would likely knock him out giving Superman or Wonder Woman the chance to tag him. The Flash could try to create a vortex around them, but even if he succeeds in dazing them it's questionable if he could take them down with a surprise punch. I could maybe seem him doing so to Wonder Woman but Superman's body is especially durable with it taking a bursting artillery shell to penetrate his skin and bullets being tanked. I don't see Flash being able to realistically hurt him.
In a fight between Superman and Wonder Woman specifically, Diana might actually have greater physical strength and definitely has far greater combat skill being the best fighter of her people, a race of immortal amazons existing since the time of Ancient Greece. The real question is if Diana has enough raw attack potency to hurt Superman which really depends how durable you think Superman's bursting shell statement requires him to be.
The other three fighters have more unique strategies. Batman is at a real disadvantage here. Not only does he not have powers, but his original story is the shortest at 6 pages. I thought his first story might have some weapon that at such a power level relatively speaking might be a significant advantage. Unfortunately he really doesn't show any. His best asset here is really his stealth ability and if he gets the drop on Hal Jordan, Martian Manhunter, or Aquaman out of the water based on a hammer dropping him then he might be able to take them out. That said in an open fight he'd lose to anyone else here just from lacking abilities and stats.
The final two are quite interesting. Green Lantern is "powerless" against anything yellow, but he shows twice in the first story alone he can still affect the non-yellow part of things. While everyone here except and ironically J'onn wear yellow, usually it's only a small part on them and so would affect Hal if he tried to push their entire body at once or something like that. Assuming that they were to fight each other, and both went intangible my presumption would be that J'onn would win because Hal has a time limit, albeit a very large 24 hour one on his Power Ring before he runs out of power while J'onn as far as can be seen from the first issue can just stay intangible as long as needed.
Assuming they were to fight otherwise, it's a bit hard to say. Green Lantern has higher showings of energy output and flight so you'd assume he'd win. That said neither show any substantial durability feats so J'onn could just as easily kill him via his eye-vision. The other thing J'onn can do is go intangible and while Green Lantern can scan for him, if he doesn't know J'onn is there in the first J'onn could potentially get the jump on him. Hal also has transmutation but once again it's not a matter of killing each other if they get a hit in, it's just the first hit wins.
Comparing either Green Lantern or Martian Manhunter against one of the first four Superman, Wonder Woman, Aquaman, or The Flash it really just depends on if the former two get blitzed as if they go intangible they basically just win but they probably can't take a hit from them.
So going to do my best at ranking them. This isn't so much who can beat everyone below them but who has the best chance against the other 6 on average.
7: Batman: Having the least content and meant to be a normal human doesn't help him. He can defeat a lower estimate Aquaman or defeat the characters with more human level durability via surprise attacks but he is similarly helpless as most people against Hal or J'onn if they turn intangible and has no way of hurting Clark or Diana at least.
6: Aquaman (assuming the fight is on land): If you take a lower estimate where his powers come from the water then Batman would beat him too. That's not really said but even looking at his feats while his swimming speed is the second fastest speed of characters here, it doesn't translate to his land speed and his physical feats are only nebulously in the same range as Clark or Diana. Clark, Diana, or Barry could likely speedblitz while Hal and J'onn can likely beat him at range.
This is where things get particularly hard as I think Superman and Wonder Woman can beat the Flash, but the Flash has the best chance of blitzing Hal and J'onn, with Hal and J'onn being large threats to Clark and Diana via energy projection, intangibility and general hax,
5: Wonder Woman: So I think Wonder Woman would have a decent matchup against Superman and Flash. Her strength statement is arguably more impressive then Superman's, though Superman's is definitely more casual and his durability is high enough that even with her skill advantage Diana might struggle against him just trying to put Superman down. Against The Flash via her large skill advantage she might be able to tag him but the Flash might be able to hurt with his strikes and even if he doesn't, with the speed gap and scientific knowledge might be able to do something like poison her depending on where they are. In both cases it's at least contested.
Conversely due to her relatively low movement speed and lack of movement options, she would have serious trouble against Green Lantern and Martian Manhunter who can maintain distance with greater speed (And flight in Green Lantern's case) and ping at her with attacks stronger then her. Even if she gets close they could simply turn intangible there's nothing she could do. Unless she starts at melee she basically can't win against those two.
4: The Flash: So I think the Flash has a good shot at beating Hal or Martian Manhunter but it's not like an incredible shot or anything. If Hal starts in the air, then the only thing Flash can do is make a vortex and as ace pilot, you'd think Hal would have some mental resistance to that. Plus he has phasing and lightspeed attacks that hit a wide area. Against Manhunter if he gets a hit in sure he'll win but if J'onn is invisible he would have to find him which might not work if J'onn can see him coming with super vision and if J'onn phases intangible Flash still can't beat him. Plus against Superman it's arguable where Flash can even put him down given Superman's durability and Flash has a worse matchup against the lower characters then anyone prior possibly losing to a stealth-ed Batman (Or Martian Manhunter), and with Wonder Woman possibly tagging him. I don't wanna disrespect just how fast he is here, he is definitely at least here but I don't think higher.
3: Superman: So Superman vs Martian Manhunter I feel like so long as Superman doesn't start at melee Range Martian Manhunter should be fast enough to go intangible and probably would against someone as obviously physically imposing as the fast moving muscular Superman. At this point MMH can simply use his eye vision to whittle him down safely. Hal is similar except with the added advantages of flying (Superman could leap at him but that would give Hal time to phase intangible) and clearly knowing who Superman is in his own story. I initially Superman higher but phasing is just a very strong ability and I don't think he can blitz either of the two phasers unless they start close range.
The last two were tricky but I eventually decided
2: Green Lantern
1: Martian Manhunter
Both these characters have relatively similar superspeed and both have phasing meaning I think it would be very hard in most cases for them to hurt each other. That said I think J'onn has a few advantages
1: His super vision and invisibility means he's more likely to get the drop on Hal
2: J'onn seems more likely to use his powers subtly and efficiently in character. Hal is characterized as something of a hot shot while J'onn is depicted as being fairly quiet and rational as a detective
3: If Hal found out that J'onn's weakness is fire he could probably win but the same could arguably be said for J'onn figuring out Hal's weakness and of the two J'onn seems the more observant type
So overall I think the Martian Manhunter would be the most likely to win if the Justice League got into a battle royale using just the feats of their first issue. I attribute this to his versatility and flexibility. It wasn't from being the best in a category it came from having strong offensive abilities in his eye vision, strong defensive abilities in his phasing and invisibility, and strong utility abilities in his super speed, super vision, and general intelligence/rationing ability. He was definitely the midpoint of all these Heroes and their capabilities.
This was a fun blog to do and if people are interested maybe sometime I'll do a Team Trial with this specific grouping of Justice League