Playing EvE really screws up my sense of scale, but just think, how many people are actually needed?
In the bridge, maybe 20-30, another 30-40 engineers in the engine, probably one crew for each turret, I was about to say turrets are AI but then what if weapons subsystem gets fried?.
I would assume in such an advanced society as the GTVA, robots will be at least slightly more advanced. And we already have robot janitors and microwave ovens.
So the 10k pple in the orion I think counts the pilots, marines who are using it as their base, and they probably even have factory farms where they grow chickins in a test tube. And what better place to carry out R&D than a heavily armored orion?
So 10k people die if an orion is ambushed and destroyed. Probably much much fewer if it was already in battle stance.
Bottom line: not counting marines and fighter pilots (though so few fighters were ever scrambled in FS, not the dozens a single orion can hold), I don't see the need for that much crew.