The higher castes are implied to be enforcers, cops and soldiers though there cavelreapers? or whatever tavros' ancestor was and they are also implied to be a part of the military so I guess we can draw from that that lowbloods were also allowed to join the military in some cases?

I mean, Condy’s goal keeping all the Adults off of Alternia is to have them not organize in non-empire-sanctioned, rebel ways. Given what we know about Alternian Society, every adult is gonna be part of the military and several branches, whether they be pilots, working on cargo ships, or on the frontlines, may depend on the specific caste, but they’re all out there with the purpose of expanding the empire more.

The enforcer caste is specifically the Purples, specially with their Chucklevoodoos keeping other castes in line with awful violent nightmares, which seems more like fear tactics and violent repression rather than actual law enforcement.

Then again it’s not like there’s that much of a difference between those two huh.