This portion struck me as odd, though:
It’s a hard slog for a new ensign (officer rank O-1) to make it to a ship command. For every hundred ensigns entering service, about 90 will stay and make it to O-4 (Lieutenant Commander), usually after about nine years of service. About 67 of those ensigns will eventually get to serve as XO (executive officer, the number two officer on a ship) after 10-12 years of service. Some 69 of those ensigns will make it to O-5 (Commander), where it first becomes possible to command a ship (a frigate or destroyer.) About 38 of those hundred ensigns will get such a command, usually after 18-20 years of service, and for about 18 months. About 22 of those ensigns will make it to O-6 (Captain) after 20-21 years of service. But only 11 of those ensigns (now captains) will get a major seagoing command (cruiser, destroyer squadron). Officers who do well commanding a ship will often get to do it two or three times before they retire after about 30 years of service.
Either those numbers are way off, it’s far easier to get promoted in the Navy than the Army, or things have changed radically in the twelve years since I hung up my uniform. Back in my day, we had an 87% selection rate for captain (O-3), only 65% or so saw major (O-4), and something over 50% made lieutenant colonel (O-5). If these figures are right, Navy officers are virtually assured O-5 rank? Given normal attrition for people who just aren’t cut out for a Navy career, it would be almost impossible not to make Commander if 69 of 100 of an accession year group cohort are selected.