Besic is redundant in that midfield. Williams is the destroyer, Walsh dictates the pace, and Besic does a little bit of both without really adding anything in particular. We'd be better off with Charsley in his place (or even in Williams' place) for those late, well-timed runs into the box. I understand that we're trying to get Besic back to full fitness but we should also be trying to win the league and Walsh/Williams/Charsley have all been stalwarts for Unsworth at various points. (Also, I feel pretty meh about Besic being back. I think he's another that has too much to learn to ever reach the required level, though it does make sense for Koeman to get a good look before he moves him on.)
No complaints about Calvert-Lewin or Lookman. They need games so it's fair to slot them in when they aren't involved with the first team.
Also... Galloway is back?
Edit: And yes, it's dumb for me to pick holes in a U23 team, especially given that Unsworth clearly knows what he's doing. I'm aware of this.