I'm not sure what good
it would actually do to leave the crew home. "Extra weight" is meaningless, as lighter starships aren't shown to outperform heavier ones. Being lighter does not make you more maneuverable, and being more maneuverable does not help you win fights. The same goes for volume: being 80% smaller than the opponent makes no difference in the ability to dodge.
Humans don't add fragility to the equation, either, as anti-inertia fields protect them from accelerations only machinery (if that) could otherwise take, shields protect them from radiation only machinery (if that) could otherwise take, and so forth - and IDFs and shields also vitally protect the machinery in ways mere acceleration- or radiation-hardening would not.
As for exposing the command center or X or Y, that's a given: something
is always exposed. If the ship can't take exposure, she ain't fit to fight anyway.