We aren't even to the average title's unit size. Hell, considering Alpha 3's most likely happening next game, which would probably involve going up against Balmar, I'd actually expect the unit count to jump.
Actually Calico currently has no place in the story unless Cobray comes and wants to relive one of his greatest victories to an unsuspecting Calico.
Calico just wanted to distance himself from being "Just another clone" so with things in in the OG verse as they are what other way could he to distance himself from them, Mass Clone Genocide. Hah give him a R- Gun Rivale Powered for lulz.