I would say that you were petty darn close, the vulture seems to be about the same length of a scorpion, limmiting the size of the crew, esp when you think of the space needed to store things like whatever powers the ship, and ammo.
For a 4 person crew: Pilot, co-pilot, communications, and weapons
I would say that the pilot and co-pilot can deal with the engines as there are two of them, the loading would have to be automated, and all crew members sit in cocpit.
For a 5 person crew: Pilot, co-pilot, communications, weapons, and engeneer
All if all were in cocpit, communications and engeneer are in back, with weapons in middle and both pilots up front.(immagine a die and look at the #5 on it.)
More than a 5 person crew: Pilot, co-pilot, communications,engeneer, and weapons team
same as 5 person crew, lead gunner from weapons team is in cocpit, a small team of 2 or maybe 3 are in the belly of the beast loading shells, in a very tightly confined space, a really crappy job: hot from the engins and heavy labor, loud from being right by the breach, and you would have no Idea what kind of danger you and the ship were in, as you were isolated from the cocpit.
I would say an 8 person crew max, before you start to have to many people.
You've just been hit by the MAC Blast!
Head to the Library and check out my FF UNSC:Unification, CH 3 is now up!