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.
Adam Sandler would play a non mutant human who as a wacky coincidence ends out at the Xavier school and has to fake his way through it. All of the mutant characters are broad stereotypical charicatures that are there for Adam Sandler to mock or to look stupid in front of Adam Sandler. It gets found out 3/4 through that he's a phony and he gets kicked out a does the whole "who needs em!' thing. X men do the big fight without Adam Sandler and get nearly beaten. Adam Sandler beats the bad guy with a comedic contrivance and the X-Men learn to accept Adam Sandler into their ranks and Xavier opens his school to everyone and stops discriminating against non-mutants like Adam Sandler.