Let's just get it out of the way straight off the bat. Ben Affleck and Henry Cavill are both outstanding actors in their own right, but they're both still unproven in the world of superheroes. While we only have the awful Daredevil film as a reference for Affleck, Cavill has already played Superman in Snyder's Man Of Steel and while he displayed a great deal of promise for the role in that film, there's still a lot more that can be done. But even if you ignore the two main characters, Nolan's Batman films are supported by such a talented cast that it's going to be extremely difficult to top it. Cillian Murphy's Scarecrow, Michael Caine's Alfred and Morgan Freeman's Lucius Fox, to name just a few, are all performed by extremely talented actors, and topping them won't be an easy ask. It's highly unlikely that any of the actors that appeared in Nolan's films will appear in Batman V Superman (for obvious reasons), so we'll just have to wait and see who is ultimately cast if the film decides to feature some of Batman's entourage.