This is water under the bridge. Aside from Stanford, I can’t think of another D1 WBB program in the country that carries 15 scholarship players. ND has 9 next season, and the Irish haven’t lost their best player to injury.
Trying to maintain a large roster of talented players, many of whom will see little or no PT is a recipe for team disharmony and transfers. Last season it appeared that UConn could have as many as 16 players. But Makurat & Chaisson left before the season. Mir & Saylor transferred out before the 2nd semester and Aubrey was out for the year.
Kids want to play. Geno doesn’t need warm bodies on the bench in case players are injured.
I have a mixed reaction to your post this time. I certainly agree completely that most programs don't need the scholarship limit of 15 players. I also agree that most kids want to play, and believe that most beyond say the first 10 probably will not be content with being a third stringer, and that could lead to disharmony and transfers.
Where I differ is I think transfers are happening at most programs at a high rate, and it has become to a certain extent a new normal. If you don't have to sit out a year that is even more true, so there is less loyalty than in the past between school and player. Schools deliberately recruit some prospects that realistically don't have a very good chance at playing time, partly because some attrition of players is anticipated.
While I agree we don't need 15, it seems like 12 or so might be good. As far as warm bodies are concerned, if a player wouldn't be used even with significant injuries, then it serves no purpose to have them on the roster. For example, suppose we added a 5th guard who wasn't very good, and if one of our four guards got injured, if Geno still preferred to use Ayanna, Aaliyah, Ice or Amari at the 3 or even the 2 than the extra guard then the pickup wouldn't matter. That extra player has to be playable in at least extreme injury scenarios to make a difference. So if an addition was just a warm body that wouldn't be used ahead of a more talented player that was playing at a bad position for them, then I agree, why bother.
Uconn has had some interesting situations with the tail end of the bench. Pulido and Lawlor for example were quite content being the 11th and 12th players that only got mop up minutes. Of course they were walk-ons so it is easy to understand. I remember being a little puzzled by the recruitment of Irwin and Bent a few years later. By Uconn standards they were not high recruits, but I kind of viewed them as upgrades over the Pulido/Lawlor level third stringers. Players who were not expecting to have a major role, but who wanted to be part of this program, and would be passable players if needed because of injuries, and way better than walk-ons.
That was a good role for them and one they would accept. But then Megan's four player class became a one player class and soon they were not spare parts, but part of the rotation getting pretty significant minutes. Then we have last year which started as you said with way too many players, but also very highly recruited players many of whom were not going to get enough time to keep them happy. I felt the same way about that overabundance, and yet in a crazy season we wound up with no backup guards for several games, and no regularly used backup bigs for several others.
You never know, so it seems to me there are several strategies if you are shooting for a roster of 12 which is my preferred number. You could just add a couple of walk-ons for 11 and 12. They wouldn't cause any disharmony or problems, but if you have to use them you are in trouble. You could pursue a second tier recruit like Kyla or Molly, that might be content in a mop up role and wouldn't kill you if needed for some rotation use. Or you could fill the two presumed third string roles with a top recruits giving them a chance to compete for a rotation spot, but with both coaches and players knowing that a couple of very talented players are going to be on the outside looking in for playing time. In that case the losers of that competition are likely transfers.
I don't want to fill the roster with 15 players either, but given the kind of things that can and do happen, I would like to see some pretty good quality in a couple of players beyond the first 10, even if that means there could be some significant turnover there.