So if some of Voyager's officers are considered "critical", does that mean they wouldn't be allowed to leave the ship if they wished to?
Because if they're allowed to leave the ship voluntarily, then clearly Voyager -can- function without them, at least in the estimation of whomever is allowing them to leave.
That is a good point. I can see the end of the episode "the 37s" where Janeway offers to let anyone who wishes stay. she walks into the cargobay and 2 crewman are standing there. She says, "Too bad, you are needed here and I'm not letting you stay. Get back to work."