There were six intially hugged in the sacrificial chamber.
Rousseau, Thomas, Joshi, Cannon and two others.
Verheiden, Miller and Verheiden are later abducted.
So there's 9.
Scar kills one. Don't remember how many are shot. Nor how many of those are killed.
Lex kills another.
So by the time they get back to the grotto, there's 7 at the absolute maximum. Lex kills another.
No way of telling whether the bodies of Bass, Stone, Stafford, Weyland or Quinn are used as hosts. Seems unlikely. And we can rule out any of Quinn's men being used as it negates the whole point of what Lex and Scar are trying to do - stop the Aliens reaching the surface.