I think they watched way too much SG-1 when they made the ranks. Colonel Jack O'Neill anyone?
Seriously, the promotions in this storyline happen A) way too fast, and B) he's commanding far too few people to warrant a promotion.
I agree with the pace, but they "bagged" themselves when they started the story how all the
With different startup they could have slowed the promotion pace so that maybe you would get promoted max to captain at the very end. Still a company (unit) officer.