I never noticed before that Crusher (Beverly) outranked Data as she's seldomly commanding. Thine Own Self (7x16), Troi (Deanna) become a commander and although it was pretty clear it was just a part-time thing, it got me wondering now that she joined Crusher outranking Data, can either of them give him an order?
To me, a second officer means that only the first and the one in charge (captain) can give him an order ; additionally those further up the ranks (admirals, etc.). Is there like a condition in the ranks? Before considering the rank, one must check the ship officer order (1st, 2nd, ...) ? Is there a precise set of condition?
Thank you kindly