But I will also add that in a 4-5 players game, villains also escape a lot more and when a villain escape, you KO from the HQ and slim the hero deck.
So the best thing to balance this out is to shorten the twists.
I see what you're saying, so more heroes get recruited each round so more twists would make it impossible. I like the "Go Back In Time" scheme from Capt. America, but I didn't like 8 heroes for a two player game, so this makes more sense. Not saying one is better, apples and oranges really, just thinking out loud - sort of.