@SuperBean66 it also might because over gaming and cosmetic style as well since we know their physical appearance changed between the X and Zero series and there are fans who exclusively favor one series over the other. Plus they’d probably be up there with Metaknight and the other “why did they make them so hard to beat?!” class. X is the literal definition of a walking tank (even as a cyber elf) while if Zero and Sonic fought on the same side it’d be a massacre (as they’re both speeders with lighting quick attacks but r no slouches when it comes to dishing out punishing both physical and special attacks). Plus we still don’t know what happened to Zero at the end of his series so they probably don’t want to give away anything that could be considered a canon confirmation.