Nigga what ? LOLOLOL
Fantastic 4, Spiderman, Daredevil, Punisher, Thor, Hulk, Ironman, Ant-Man there are dozens of standalone movies they can do. They don't need to do a mashup.
As for X-Men, dude the X-Men is such a big universe in and of itself and waaaayyy more in depth than the Avengers so yeah they can easily do better movies than the Avengers. X-Men have touched on racism, classism, sexism, homophobia, politics, war, love and so much more in their comics. Plus the X-Men have more leeway to be grittier. And off that you can do standalone films for dayum near every X-Men, Wolverine , Cyclops, Xavier, Gambit, Jean, Bobby Drake, Cable, Bishop, Deadpool shit even its villains. Marvel is prolly gonna start with the general origin story and then build it up to lead into House of M and/or Messiah Complex arcs. One way or the other they're gonna put out at least 10 x men films.