You know, that was one badass thing about Kamen Rider crossovers back in the day-NO POINTLESS FIGHTS. They recgonized each other as fellow WARRIORS OF JUSTICE and fucked the **** up of any bad guys in the area
..and that's exactly how this movie should go with some allowance for villains using mind-woogy tricks on the heroes and whatnot.
But then I guess they want to service the fans various "my dad can beat up your dad" fantasies. I don't really get needing to have the love of one's favorite hero validated by that characters ability to beat up someone else's favorite.