Everyone has differing ideas on it. Me? I try to stay away from the matriarchal doe. She's the one that's usually at the lead of a line of doe on the move. I also try to stay away from tail-end Charlie. By this time of year, that's often a button buck.
Mature or not, you usually want to go for the second or third doe in a line of 5. In groups of 2, go for the smallest. Singly? It depends. It may be a button buck, it may be a barren doe.
Why not the matriarch? She is the one with the most knowledge about how to keep the herd living. The longer you can keep her happy, the greater likelyhood you will have a happy healthy resident doe population on your place. I made the mistake once of killing off the lead doe. Basically, it disrupted a stable movement pattern of the herd. They stopped using the area as a travel corridor, and screwed up hunting out of one blind almost permanently.