Cap is a Fighter, Battlemaster, but a Paladin when he carries Mjolnir. Second Wind: I could do this all day.
Thor is an Eldritch Knight.
Hawkeye you'd think Ranger, but I would argue he's Fighter - Arcane Archer.
Iron Man is the one I'm having trouble with. I feel like he could fit into pretty much any class, especially if you think of his tech as magic spells. Is he a Bard?
For some, sure. Pathfinder 2e doesn't allow full multiclassing, though, which some characters would probably benefit from in terms of adaptational accuracy.