I’m not talking about stuff like O’Brien’s hollow rank pip, I’m talking about stuff like “Why make Chakotay a lt. commander rather than a full commander?”
It seems like there was at least some forethought put into who has what rank, but it’s not clear to me how much thought, nor how much meaning was supposed to be baked in to those decisions.
For example, Dr Crusher was a full commander from Day 1, matched only by Riker on the main cast. Was that supposed to signify the authority afforded to the CMO? Was it supposed to be blatant enough for the audience to “get” it?
One of the most prominent examples is Sisko starting his series as a commander. Again — was that supposed to signify that he was more junior, a younger officer?
Behind the scenes, I wonder if we can trace a waxing and waning military influence in the writers room over the years. I know Roddenberry served, and I think some of the early TNG writers did as well. But I feel like that became less common in later series? (But I don’t know for sure.)
I think it’s striking that rank is significantly downplayed on DSC, except for Burnham and potentially Saru.
A couple of quibbles that no one else seems to have brought up. Ensign Tilly was not promoted to XO - she was assigned to the position of acting XO while remaining an Ensign. The designation of “acting” makes it clear she’s just holding down the slot temporarily until Saru makes a more permanent selection, and makes it much more tolerable for those she’s now in charge of despite the lower rank. It probably wouldn’t have been tolerated (by the Admirals at Command) even in the lax standards of Starfleet, but even ADM Vance realized Saru had to pick from the tiny crew he brought to the future with him, so he let it go.
As for Ezri, again, remember that rank and position are only loosely connected, while rank and specialty (Counselor, science officer, engineer, navigator) are COMPLETELY unconnected. Ezri is a counselor because they wanted to make her distinct from Jadzia, and is an Ensign to highlight her inexperience both as a person and in dealing with a symbiote.
But yes, it does seem like the writers’ familiarity comes and goes. I swear there are at least a few episodes (and I can’t remember which series, because I’m alternating between three right now) where people refer to a Lt. Cdr. as “Lieutenant” instead of the proper term of address, “Commander.”