Such a fumble. I wanted X-Men ala The Authority. It did not deliver. At all.
I'd try again though, slightly tweaked with the new era in mind:
Ditch Piotr/Illyana/Danger for Apocalypse. He's the big guy, teleporter/mage, and techno-specialist all in one, and cooler than all of them combined.
Ditch Scott and Emma, replace with Synch and M. Synch takes Hope's place too.
So with that in mind:
Storm as leader, the only one who can keep the triumvirate of Magneto,
Namor, and Apocalypse in line.
Monet
Synch
and since we still have so many open spots add:
Rictor as earth priest, dating Blue Zaddy
Marisol/Flourish, but rename her Cultura as the fungus/plant elemental
and might as well add Logan for the heck of it.
Trinary, Sage and Prodigy are key support characters, along with Triage, Forge, and Mondo.