Oh yeah, the Legion is totally fucked up, I agree. I like his idea of eventual "utopia" but man, I am pretty sure it can be done without the slaves and rampant murdering and pillaging. Iirc correctly he even goes as far to say that if the settlements they raid take "too long" to decide if they wanna join, they just fuck 'em up with no other option. What's worse is it's made obvious after the first few quests with them that the cause has been totally lost on his subordinates, they may say "Cesar will enlighten the nation" and what not but they act like power-hungry kids who have finally been given something to call their own. So he moves on, leaves these kids to tend to the territory they've now conquered but these guys have only known rape and violence for likely years. They really gonna hold that back when encountering problems in their new cities? Probably not. Then the cycle continues.

I think there are a lot of parallels between the NCR and Legion but NCR, imo, is the short-term lesser than two weevils.