A: To review:

a) It is an established ruling that a Captain can “command” (steal) any crew member, regardless of whether they are from the same series… unless that crew member is already with their appropriately-matched captain.

b) It is also a stated function of the two “Red-Shirt” crew members, Ensign Smith from TOS, and Tasha Yar from TNG, that they must be taken in place of the intended target Keeper of a steal or trash action.

So what happens if, say, the player with Kirk tries to command (steal) Spock from the player who has Picard and Tasha Yar? The “power” (weakness?) of the Red-Shirt is that they must be taken in place of the targeted Keeper, BUT the ruling for mixing Trek decks is that Captains cannot command (steal) crew members away if they are already with their assigned Captain, which Tasha Yar is, since she’s with Picard.

So which rule supersedes the other?

Andy has declared that the need to throw themselves into the path of danger takes priority over the importance of staying by their Captain’s side. Picture the scene: two starfleet crews interacting, a dangerous situation unfolding, one Captain calling out for help. “I’ll go, Captain!” says Tasha Yar or Ensign Smith.

It is the intrinsic nature of the Red Shirt to volunteer or leap into the path of danger, and it overrides their Captain-preference. After all, if decks were not mixed, and the only Captain in the game was their own, they would still jump into the fray, so clearly the presence of their Captain is not enough to temper their impetuous behavior.