Captain America is the leader of the Avengers

Mr. Fantastic is the leader of the FF

Cyclops-leader of X-men

Punisher- can represent the loners but he also founded the Marvel Knights and kind of acts as a co-leader. if the Marvel Knights were ever ranked, punisher would be #1 so its appropriate to choose him for this match.

what happens when the leaders of marvel face off with out the help of their powerfully superior followers?

i say cyclops. he's coo.