Modern turrets rarely have any need of actual crew. Though they often do have a position for the gunner as well as some one being assigned as the gunner. Centralized firing control room (i.e. gunnery control) is where the action takes places. In older guns most of the crew assigned for the gun were loaders as ammo loading systems rarely were fully automatic. In scifi weapon which apparently does not need ammo there is no need for loaders. So it could be assumed that there would be a gunner (or 2 - 3 for bigger/longer ranged ones) for each turret for local control as well as one per every few turrets in control room plus the gunnery officer.
Then there would be command crew, pilot, navigation, command, sensor, comms, the usual as well as some other critical personnel. And those times 3 or 4 according on how many shifts the crew operates. Plus reserves. Though duties can be shared so number could be lower than that (for example gunnery officer could well be part of the command crew in one of the shifts). And then you still need the engineering and maintenance crews, medical, flight staff, clerks, marines/security troopers, etc...
For flight staff for say a fighter of the size the ones seen in FS you could estimate that you'll need the pilot or two (and possibly a gunner) to fly it, and several mechanics/engineers to keep it flying (from size you could say from 2 - 3 mechanics for Uly to something closer to 10 or so for Ursa and the likes). And then you'll need the rest of the ground crew. Flight ops, landing officers etc.
In the end the numbers could vary so greatly that there is no real point in trying to guess them without better info to start with.