Caesar's plan/intent, from what I recall, was arguably a bit more batshit or high-concept but I could be misremembering. It explains why he doesn't care about administrating conquered territory effectively because he's of the view that once the NCR is conquered, his Legion and the fallen NCR would synthesise into an optimal system that was greater than the sum of its parts; I don't know whether this would occur when he's still alive or after he's dead, but he cites how absorbing the different tribes into his Legion usually leads to something or other getting absorbed, and whatever they gain from the NCR will change the Legion for the better.
From a meta POV, there might be a reason why it's called "The Legion" and not "Rome 2" or something similar. It isn't a nation, not really, it's an army first and foremost. Everything is done to facilitate and supply this army as cheaply and as efficiently as possible, because Caesar's sole objective is to conquer the NCR, because thereafter the perfect nation to rule the wastes will come out of it.
It also could be my interpretation that I'm pulling from my ass or straight from Caesar's mouth, but I think he created the Legion intentionally in the NCR's image, because the end result of their combination would have the strengths of both with none of the weaknesses.
His huge ego meanwhile might've contributed to this lofty objective, or the objective is what caused the ego, but like House, the NCR, or the player, he believes achieving his goal is ultimately what's best for everyone in Vegas whether they agree or not. Something something War never changes.
Sorry for the double post