Historically the JLA has been significantly more powerful than the Avengers. I don't see this team living up to the JLA history by any means. This isn't a Marvel diss... just not anywhere near as powerful a team.
Superman - Thor = Close
Wonder Woman - Spider-Man = Wonder Woman
Batman - Cap. America = Cap. America
Green Lantern - Silver Surfer = Silver Surfer
Flash - Iron Man = Flash
Martian Manhunter - Hulk = Hulk
Aquaman - Namor = Depends.
Superman > Thor and Asgarde isn't a factor in the DCU
WW >>>>> SPider man
Batman = Cap (no favorites
GL = Surfer (Hal or Kyle)
Flash >>>>>>> IM
MM >>>>>> Hulk based SOLELY on his role in the JLA. MM is a great bruiser if he needs to be, which is ALL Hulk is. MM also is a telepath, space traveler, think tank, etc. He filled a role Hulk cannot.
Aquaman = Namor
The Supes/Thor gap, WW/Spidey gap, and Flash/IM gaps are too big.
Hulk isn't gonna work in the DCU as a member of the JLA. First fight against Darkseid and he's useless.
It really depends on which mental incarnation of the Hulk that you are speaking of. Bruce Banner in the role of the Hulk could very easily replace J'onn, and as far as tanks go, J'onn would have a far tougher time stopping Lobo, Grundy, or some other super tank.
The Surfer would waste a GL on average.
Spiderman may not be able to defeat Diana but he would bring more to the team than she does in terms of brains. I also wouldn't sleep on him, he has some very impressive feats.
Thor could easily replace Superman when speaking of power stunts, and handling villains.
Captain America would beat the hell out of Batman in a real fight, and he is a better tactician. Batman is smarter, and can solve mysteries better but they have Ironman on the team.
The flash would defeat Iron Man in a non prep battle, but if Tony put his mind to it, he would beat the Flash. Tony is all about prep. In terms of smarts, I'd go with Tony over Barry. After all Tony has more in terms of resources than Barry, and his tech is simply more practical.
Like I said they would do just fine, although I would have replaced Spiderman with Sersi, but this team would do very well in the DCU. You may just not want to recognize the marvels for their individual talents, and the things that they can bring to the table.
True, but don't forget Stoic, MM is almost never used as a tank - he's used more as a telepathic coordinator, sharing battle plans. Yes, the Avengers have Cap, but its a real advantage having the ability to share it amongst your team mates at the sped of thought.
Then of course, if you want to use BannerHulk, then his usefulness as a tank is decreased, and vice versa (not that you need a thinker, when you have Tony).
The Hulk can and has worked well in a team environment. Have you forgotten Diana's blood lust? The Hulk can jump. Tony could also equip him with tech to fly.
Spiderman has brains that Diana never has, so he isn't as useless as you may at first believe.
Aquaman is not greater than Namor. The only thing that we have on panel is Namor resisting Aquaman's TP while all of the others fell. I didn't write it, but there it was on panel. Namor has the strength advantage. I'd call them near even.
Thor has more power than Superman, while Superman is stronger. This is not a battle between the two, but a comparison to how well the Marvel's would acclimate in the DCU.
Who needs TP when you have communications technology?
Tony can build tech to allow for the entire team to operate in any environment short of a black hole, and that within itself is up for debate.
Namor has been poorly written and is more than a simple brick. Namor if fitted properly is quite the powerful blaster character if he were ever written to be geared up with high powered electro rods.
I really believe that this team would do well, and if they were in the DCU, you could be certain that Steve would likely recruit many other super powers. just think outside of the box, and you will realize that this team could replace the DC team.
A good question is how well would the DC team do in the Marvel U. I think that they would do well as well, but they would have their difficulties with guys like Galactus, Mephisto, Doom, Annihilus, Thanos... you know what I mean?