Writing Help (please?)

Okay, I know that in fiction, there are main characters and supporting characters, protagonists and antagonists. I am wondering, are you allowed to have more than one main hero? To clarify: Can there be two or more equal heroes? None of them do everything or protect everyone, and they all add to the team.

Can you just imagine a team where no one is the perfect, super-awesome hero? There may be a leader, but he is no better than the rest. He has powers that make him useful, flaws to make him normal/interesting, and weaknesses to allow his teammates opportunities to save him. Now, imagine everyone on the team like this. Each one would have the chance to save the day, in one way or another.


Is this kinda stuff allowed or is it breaking some ancient writing custom of "only one true hero"?