True. I think unlikely friends wouldn't suit Dez's personality, but if the two were rivals, I think Dez would respect Xander for his strength. Dez is the kind of person who could even respect his worst enemy if they proved themselves to be strong.
Rivals or unlikely friends had been the two options I'd considered. Rivals for the reasons you described, similar background and views that could cause a butting of heads. Unlikely friends could be possible, but less likely. It just depends on whether you want Dez to develop positive or negative relationships to begin with. I'm good either way.
So, I'm thinking they could be rivals/enemies, since my character doesn't really care for other rich kids. lol. They do have similarities in that they both think they are the best, and even though they could be enemies, they could recognize each other's strength and respect it.