I think he needs to trust the squad a lot more. He seemed to earlier. Since the restart though, it's been the one set of players and that's it. There was plenty of ways to rotate the squad with what we have and keep everyone more fresh, but he persisted and now it might cost us. Fred and McTominay are perfect examples. They are both good players and worth their place in the squad, and had very good seasons. Ole hasn't used them at all since the restart. Yes Matic, Bruno and Pogba are better, but now their level has dropped due to tiredness, and that was easily preventable. We could've used them as a base in midfield with Bruno as the 10 once, Pogba as a 10 once, and then used the matic/bruno/pogba trio for the others to give some more rotation in the league. More than good enough and it puts faith in the players. Ok in attack the depth isn't amazing, but still, Ighalo and James could've been used more to at least rotate each of Rashford, Martial, Greenwood out of the starting 11 at least 1 time in the league (couldn't have asked for nicer fixtures). Fullback as well, Williams didn't get a look in until Shaw got injured, even though he can play left or right back. All it would've taken was a start once at left back, once at right back to break up a big run of games to keep Wan Bissaka and Shaw more fresh. Instead, Shaw is injured, AWB looks knackered.
Rotation not only keeps main players fresh, but it keeps squad players engaged, and keeps the main players on their toes! Instead, they barely get a look in and when they do, they aren't in form and are probably not happy with their playing time and that usually doesn't bring out their best level.
Anyway, next season if we sign Sancho, I think we'll be much better with depth. Or should be. We can rotate and use 3 of Rashford/Martial/Sancho/Greenwood, and then further depth with James and Ighalo for full rotation games. There's not loads that we need, but a big part is the manager using them properly. I'm not sure Ole can trust the team if he doesn't put his absolute best 11 out there.