Here's what we decided:

Adam Sandler would be Wolverine of course. He would drunkenly chase after another student, who could morph into a penguin, in a golf cart like the opening of Billy Madison.

Kevin James would be Professor X. I know this might seem controversial at first, but hear me out: Instead of a wheelchair with Xs on the wheels, it would be a Segway with Xs on the wheels. He wouldn't drive it around because he was paraplegic obviously, just cuz he's too lazy to walk.

Rob Schneider would be a new character: Jose. The groundskeeper of the X Mansion that just so happens to be a racist caricature of a Mexican migrant worker.

Nick Swardson would be Beast.

David Spade would be Cyclops.

Peter Dinklage would be Magneto.

The girl from The Wrong Missy would be Mystique.

Vanilla Ice would be Iceman

If you have any ideas to add to this, feel free.