This is an opinion from a Barca fan’s point of view, so take it with a pinch of salt.
The problem with the current Manchester United is that you guys are satisfied with 8/10 players.
Luke Shaw is a solid left back. He is sound defensively and not bad going forward. But when you compare him to Jordi Alba or Marcelo (before this season), he just doesn’t compare at all. He’s not even close. Guys like Marcelo and Alba can win you games on their own.
Chris Smalling seems at least respected on here. He’s a solid defender, but very limited on the ball. Unlike say Chiellini, he’s also not that good of a defender that it negates his limitations as a football.
The reason to why I mention Smalling and Shaw is because they are generally rated on here, unlike guys like Jones and Young.
It’s fine to have some 8/10 players, but if all your outfield players apart from Pogba are decent-but-not-great, then you will get decent-but-not-great results.
Think you are being very generous, we have a lot of 6/10 players and two or three 8/10 players that are performing more regularly 6/10. The only player I would worry about losing would be DeGea, despite his recent form, in my opinion, he is the best keeper in the world which makes him hard to replace.
As for the rest, its more worrying about who I would want to keep, as there isnt a single player I am totally convinced by. I think Rashford is over rated, but I do like him and he is talented, Shaw, very much the same as you, he is a solid left back. As for the rest, its probably players I would like to stay as SQUAD players more than starters, its mainly our bigger signings I most want to leave, Lukaku most certainly at the top of the list.
I would like us to keep DeGea, Shaw, Smalling, Dalot, McTominay, Rashford....only half of them as probably starters though. I actually think our squad is good and we have a couple of very exciting youngsters that can possibly come through......but first eleven quality I actually think up to 8 spots need replacing, which is a huge job and to fix everything we would need a football manager type transfer window this summer with 10 or so players out for £300m odd and an actual £500m spend....basically, pretty much all we have done in the transfer market over the last 7 years, needs to be done in one window....but signing the right players rather than virtually all wrong ones, that just how abysmally poor our transfer business has been, pretty much every window since we signed Van Persie