As near as that would be to the Phoenix Saga, & with the popularity of Wolverine even then, I'd say you get something very like OTL's films.
The characters are probably closer to OTL; I doubt Rogue is the teen she was in the film. I'd guess Kitty takes that role,
per OTL.
Casting choices I'm very unsure of. I'm picturing Alyssa Milano as Kitty, somehow (a touch too old?), & there's a reasonable chance Patrick Stewart still gets the nod as Charles. (Stanley Tucci might be a good choice. So might Brian Dennehy.)
They're both too old IMO, but I could just picture Kyle MacLachlan as Scott & Jennifer Connelly (with a dye job) as Jean.
I kind of like the idea of Colm Meaney as Hank (tho TTL, he wouldn't appear; maybe as Wyngarde? Better still, as Shaw?

)
Donald Sutherland might make an interesting Magneto (presuming he appears) or Gyrich.
Alan Rickman as Wyngarde?
Keanu Reeves as Logan? (Maybe Christian Slater? Kiefer Sutherland?)
Maybe Robyn Lively's a better Jean (tho being about the same age as Alyssa makes that problematic...

). Maybe Moira Kelly?
I'd pick Iman as Ororo in a heartbeat.
Kevin Spacey as Wyngarde could be excellent.
Keri Russell as Kitty? (Younger than Robyn by about 4yrs, which would be about right, if Robyn's made to look a bit older, or Keri a bit younger.)
If we're willing to bend a little, Brandon Lee would be an interesting choice for Logan, & able to do his own stunts.

(Would this butterfly away "The Crow" & his death? Or does he suffer a fatality on set here, instead?


Would this also prevent him doing "Rapid Fire"? I'd hope not.)
Hugh Laurie would be a really interesting choice as Charles. We know (based on "House") he can get the American accent down... I'm not so sure him bald works, tho.
Catherine Bell as Jean crosses my mind, but I'm not sure she'd done anything enough to earn a starring role yet. A single episode of "Dream On"? Or not even that, yet?