/\/\ ... kekeke ...
Quicksilver, Namor, and Black Panther tecnically are not an Avenger. (True, they had a short stinch in being a member, but that is just how Marvel mix and match every now and then, like how they are putting in Spidey as a member presently.) The original/founding members never had these lone wolves. And do not forget there are actually TWO Avengers team -- East and West Coast; thus there is still Wonder-Man, Hercules, Mocking Bird, Tigra, and others (the on and off members like Human Torch, Spider-woman, Moon Knight, Silver Surfer, Dr Strange, and even Wolverine etc.).
For sake of argument, we will just focus on the core (original/founding) members of JLA Vs Avengers.
JLA:
Superman
Wonderwoman
Batman
Green Lantern
Flash
Aquaman
Martian Manhunter
Avengers:
Caps
Thor
Hulk
Iron Man
Hawkeye
Wonderman
Tigra
Scarlet Witch
Mocking Bird
Vision
Hercules (Like Thor, he is a God. Unlike Thor, he is 1 of Top 10 most powerful, at 5 or 6.)
Wasp
Antman
Given this original roster, with the exception of Superman, it is pretty clear how JLA will fair ... KEKEKE ...
(And arguing all the NEW or recent powerups of each/both teams is just ludicrous, because both teams are invincible at that point, even Batman (
), a la the "Hellbat armor", which according to the comics, if he uses too much or overuse can make him mental, or drain his life away towards death -- so says the comic.)
But just for kicks and giggles, here is my take of JLA Vs Avengers (<, >, =, >=, or <=), as they were originally, minus all the ridiculous/dumb powerups nowadays.
Superman >= Hulk
Superman <= Thor (because it known/given Superman is weak/bows down to magic.)
Superman < Hercules
Caps, Ironman > Batman (whatever "BS" being argued in Batman's favor is just
)
Wonderwoman > Mocking Bird (she's human, no real super powers)
Wonderwoman >= Tigra
Wonderwoman <= Wonderman
Wonderwoman < Scarlet Witch
Green Lantern > Hawkeye, Wonderman
Green Lantern < Vision
Flash > Caps, Hawkeye
Flash < Hulk, Thor, Hercules
Aquaman < Hulk, Thor, Hercules, Vision
Martian Manhunter >= Vision
Martian Manhunter < Hulk, Thor, Hercules
Bottom line, it is the team with the
MOST UMPH! JLA technically only has Superman in this case. But as stated, and is confirmed in the comics -- per DC -- Superman is weak/loses against "magic" which both Thor and Hercules possess and are, being mythical Gods. Recall -- per DC, Superman can, was, and is defeated by Shazam/Captain Marvel and Black Adam, who are super hero of magic -- created by magic. The only survivor I foresee in the JLA should these two teams face off in a "Death Match" is the "Flash" simply because he can RUN AWAY/OFF into another universe/timeline, if he doesn't get trapped by the Scarlet Witche's magic/telepathy first ... KEKEKE ...