In a physical fight Fantomex shoots guns, Mystique shoots guns, Gambit can make anything and everything explode. In the past Logan and Gambit have built up a reputation for being notoriously difficult to mindread but here they were most useful to Xavier for the distraction to SK in the physical realm, is that so hard to accept? Fantomex was just adequate in his role in the fight, what Xavier primarily wanted out of him was a body with a face that most people weren't familiar with as belonging to anyone yet, that's obvious enough.