Probably because it's supposed to be left to the players. Really hard to have a group where they are all the same rank.
Not really - positional authorities can make up for that quite easily.
Top Down
Commanding Officer ranks everyone
Vice Commander (if any - use on ships has varied over the years - more off than on)
Executive Officer
—— below here, rank usually trumps position; position often beats date of rank)
Operations Officer (Note Data holds this in TNG, and Ranks LaForge; we see Data take the center seat throughout TNG)
Chief Engineering Officer (LtCdr Argyle for a while, later Lt LaForge)
Senior Helm Officer
Senior Gunnery Officer
Senior Subcraft Pilot Officers.
Assistant Chief Engineering Officer
other line (Command Division) officers by date of rank
Other Operations officers by date of rank
Science Officers by date of rank
