How many crew members sit inside each unit in Homeworld and Deserts of Kharak?
I don't know of a canonical answer but I can say that in several later cinematics (in Deserts of Kharak), there are other crew either implied or actually shown - for instance a co-pilot in the S'Jet baserunner - radio messages about picking her up in the opening cinematic must be coming from the co-pilot.
In Homeworld 2, one of the missions involves picking up crew for the mothership. According to what I could find online, the Mothership has a skeleton crew compliment of 8000 (not confirmed).
I've found this thread which discusses crew complements, and although I'm not able to verify, some claim the following numbers:
- Taiidan Minelayer Corvette: 3
- Scouts, Recons, Acolyte, Mimic: 1
- Kuun-Lan: 1150, 2000 in cryo
- Mothership: 8,000 skeleton
- Kushan Heavy Cruiser: 150
- Ramming Frigate: 5
- Taiidan Assault Frigates: "Twice" as much as equivelent frigates.
- MCV, ACV: 2
Essentially there's no canonical answer that I could find, aside from the very vague guidance offered by cinematics.
EDIT: I do have in my possession an original paper manual for HW1, I will have a read of it and see if there is any mention of crew numbers later.