I'm with Shonen on that too, the names don't really... do it for me, to be honest. I mean, if everybody else is fine with them, I don't hate them enough to not be on board with it, but eh.
Since the Coven is like a secret society of sorts (well not so secret anymore), I always imagined they'd have a ranking system like the Freemasons or something, like "Mage 3rd Degree", "2nd Degree", et cetera. Not necessarily in that naming scheme, but kind of like the ninja system in Naruto too. Ranks aren't specific positions but "levels" attributing to skill and the difficulty of missions and tasks assigned to them. Sort of like martial art belts too.
I wanna suggest the following ranks, which would be more like honors or a status, rather than a military rank:
- Grand Priest - leader of the Coven
- Draco Magicae, Latin for "Dragon Magic" - second-in-command, the highest rank given by the leader, symbolizing an honor bestowed upon the most skilled member by granting them a name akin to that of 'Dragon'.
- Summa Magicae, Latin for "Highest Magic" - senior Coven members, ones that would also be in command of other bases or outposts.
- Magna Magicae, Latin for "Great Magic" - intermediate level, likely the ones tasked with high-ranking positions within every base and the headquarters too.
- Adept, the rank-in-file members. (still thinking on a Latin name for this rank)
If this idea works, we can always rearrange those names too, I just put down what immediately came to mind.
As for structure, I wanted to see the Coven be way more spread out. Sure, they have the main headquarters castle (which I wanted to see if everybody liked the idea of a floating castle-like structure occupying a parallel dimension within the human world, much like the Royal Palace in Soul Society), but also, I thought they might have several bases scattered all throughout the human world. After all, with Kido, they could easily have the means to jump between bases at any time, so they'd always be unified and organized but also spread out to cover a massive stretch of area that makes it harder for the Soul Society to deliver an all-out offense. It also creates new roleplay routes for different stories pertaining to specific outposts and whatnot.
Also, have we settled on a leader and second-in-command? I mean, there's no need to make the decision now since they likely won't appear in the story right away, but this is something we should square away whenever possible.