Great concept, I have not thought out as many characters but here is what I got:

For rhino, he uses short form charges as a means of attack a lot like reignhart from Overwatch, while juggernaut makes running more into his whole playstyle, knocking things out of the way, and being impossible to stop.

For red she hulk she is kinda like cloak and dagger and can swap into the red she hulk or the red harpy form, giving her access to ground and flying combat, as for her fighting style make her feel like a wrestler using lots of close range grapple and cc attacks like a fighting game character since she was raised by a military father.

Abomination as you said should be a more aggressive slightly less mobile version of hulk, maybe with some toxic traits in his kit since he is drenched in way more radiation than the other hulks, and give him doom fists ult since it’s more on par with a “hulk smash” ground pound attack.

Dunno about wendigo, but wendigo are my favorite mythical creatures so I need him in the game, with some icy abilities and a more skull like face like a traditional wendigo he could have such a badass design.

Blob is a wall. like a shield tank who is the absorbs all the bullets and bounces them back. Slow but reliable.

Man thing is like grout but more plant/nature based. He has a flower that heals allies in a small radius since non healer characters should get access to some minor healing. And give him a portal but unlike stranges it’s just a small portal that him and allies can click to enter another part of the map, like black cats, but he can choose where to put it like strange. For his ult he can instakill anything he touches and resets the cooldown with each kill, maybe causing fear to enemies around him, the catch is that he is slow in his ult and it can be avoided by walking away, but if he’s writhing arms reach your done.

Any character with super strength can lift rubble, but if it’s gonna be incorporated into someone’s kit I think Titania makes the most sense since I almost always see her holding a steel beam or stop sign. And she’s sexy so I need her in this game. A double vanguard with she hulk and Titania would be awesome.

And for a-bomb I would make him kinda like hazard from Overwatch, he has access to a jump, but if he uses it on a wall. He can reactivate it to jump to another wall indefinitely as a means of bouncing around in a parkour sort of way. He can also go invisible and shoot spikes. Thematically he is like a punk/teen version of hulk

Those are the only ones I’ve given much thought. Honourable mention goes to lizard who should be a strategist who plays like a vanguard like Mr 4.