There is a fair amount to be said in favour of keeping the rank of captain scarce. The senior officers tend to be some of the most consistent attendees and if we have to run fewer ships than we have captains, it is less jarring to have a commander serve in another position aboard ship.
I guess that means I am suggesting that Captain is also a suitable rank for a battlegroup commander otherwise I was going to suggest stealing from the airforce and using Group-Captain even though I know the meaning in the airforce is completely different and not a comparable rank. But it sounds right and its meaning is very literally accurate. Outside the US the position (not rank) commanding multiple ships temporarily is Commodore, but generally they are stuffy, obnoxious bad-guys. Also we are playing Star-Trek and Nobody really wants to be promoted above Captain 🙂 For this reason I really like the rank of Fleet Captain for our division commander.
It really should not be a problem to have a lot of Lieutenants. The vast majority of Starfleet officers actually seem to be Lieutenants and they are seasoned, capable officers ready to command in a pinch. The long serving lieutenant is also a trope of Napoleonic naval fiction 🙂
Starfleet also definitely seems to use Lieutenant Commander as a department head with only a technical qualification to command. So I would have no problem with making it not a senior officer grade.
We already have two grades of Lieutenant. But we could institute higher grades of lieutenant, such as Senior, First, Chief, or Master lieutenant (to steal from warrant and petty officer grades) or possible Major-Lieutenant. Probably Senior or First would be my preferred option.
I really dislike the term Captain-Lieutenant. It is said that way round because of the languages that use it. If I understand correctly it means Lieutenant-Captain (as Germanic languages would form it) which is the same thing as a Commander.
