I feel like the level system should be used mostly for the RPG addon and less for the ranks. I feel like there are people who would be a good SGT or higher, but can't because their level is holding them back. So rather than levels being the deciding factor in whether or not someone gets promoted, the deciding factor should be ability, with the level helping to decide but without the decision hinging on it. Just a thought. Also, maybe make it so Commanders can promote their troops up to SGT independently, but then to promote a particular troop any higher they need to first go to Priest or someone of equivalent rank and neutrality. Basically, someone with more authority than a CO and isn't tied down to a specific regiment.