I just rewatched the Star Trek: The Next Generation episode "Descent" and I'm somewhat baffled.
After Data goes missing, and Riker is already on the surface, this occurs:
PICARD: I'm going to start sending down other away teams. Set up a command post and begin mapping out a search plan.
RIKER [OC]: Understood, sir.
PICARD: Picard out. I want to use the shuttlecraft for low level reconnaissance. Have the designated pilots assemble at main shuttlebay.
LAFORGE: Aye, sir.
PICARD: And all available personnel, including you and me, will begin to put together four man away teams. We'll leave a skeleton crew on board the ship.
LAFORGE: Who'll be in command of the Enterprise?
(later) CRUSHER: Any last orders?
Much of the rest of the two-part episode occurs on the Enterprise with Crusher, Taitt, Barnaby and Salazar, who, I believe, never show up again.
So this all seems pretty strange. Picard knows there are Borg around and for some reason decides he needs every available boot on the ground, including himself. And he leaves Crusher in command of the ship with an inexperienced and skeleton crew in non-Federation space when there is a bogey about.
Is there some plot point I missed which explains the necessity? Alternatively, is there some out-of-universe story-telling explanation for why the writers made these strange choices?