The same office politics control both. It’s even almost literally the same form. The difference being, enlisted advancement is done through tests and combining that with an evaluation score (where the office politics comes in, and if you don’t have the highest eval you aren’t getting enough points) that combines with points from awards, education, and other shit (and office politics determine who gets those awards, who goes to the extra schools, etc). Then anybody that’s above a certain point value for their job group makes the next rank. There’s a set number of billets and they chop the top scoring off to fill them.

Once enlisted hit the beginning of their “senior leadership” level promotions the form stays, but the tests go away and instead you have a board that you report to that gives an oral exam of sorts and then they all weigh in together and look over your packet and they have to majority agree. At this level you’re basically applying for specific billets and the rank promotion comes with that billet, so it’s like a job interview and all of the office politics that go into that combined with a permanent record of your military career that would make a high schools permanent record blush. You see where the good old boys club comes in here.

Officers are promoted solely through spending enough time at the lower ranks (no tests ever for the failsons, just show up on time buddy) and once they reach senior leadership levels they follow the same process as senior enlisted promotions except their board is mostly made up of the highest senior enlisted at the command and a couple officers. Same good old boys club, because it’s entirely dependent on the board and office politics who makes that promotion/gets that posting.

Whole thing is designed to insulate senior leadership and officers from consequences and discomfort while offloading the work onto an increasingly shrinking body of lower enlisted who increasingly aren’t giving a shit about doing things the right way with a leadership that has all but mentally checked out in light of increased struggles that don’t seem to have any coherent grasp of or plan for addressing.