This simple point really goes without saying. As things stand, there aren't enough heroes in the Marvel Cinematic Universe to make this movie possible, so we certainly need to see more added before it's anything more than a pipe dream. The likes of Doctor Strange, Ant-Man, Wasp, Ms. Marvel, Black Panther, Namor, She-Hulk, the Inhumans and the Defenders - and potentially more - should all be established characters before this idea comes in to fruition as a movie, so that they have time to choose a side to fight on. Without enough characters to make two small armies, the movie would have no right including the word "war" in its title.
