Note: Those unfamiliar with the nuances of military ranks and positions may find Ennesby's comment confusing. Adjutant is a position held independent of rank, and Ennesby hasn't been given any rank to speak of. He isn't enlisted, and he's certainly not an officer. He might be a civilian contractor, but then again the entire mercenary company falls into that category so let's leave that can of worms unopened.
Okay, not entirely unopened. We'll peek inside, because Para Ventura was, in fact, a civilian contractor aboard the Morokweng, and when she enlisted with Tagon's Toughs she came on as an ensign, and was promoted to Lieutenant. It's not important to understand the exact circumstances of the recent revocation of her commission, but as a point of information she, too, is currently rank-less. Coxswain is a position that is held independent of rank (just like adjutant,) but it is extremely unusual for a coxswain to have no rank whatsoever aboard a boat full of enlisted troops, NCOs, and ranking officers.
And by "extremely unusual," it's a big galaxy with lots of people in it. Somewhere this is probably always happening. And right now it's happening here.