I do think I agree with you. The Avengers are flawed. Iron Man is human, Captain America is out of his time, Thor is arrogant and otherworldly, Hulk is a monster. When you have a team with powerful characters weakened by their flaws, they are strengthened by their companionship. When Hulk is less monstrous, or when Thor is too relatable as a mortal, they become too perfect and they might as well be Clark Kent.