All easy to say in hindsight.
Romero was looking pretty classy until he got injured. Not a lot we could do about that one.
Royal was a good fit at the time. Can't blame our recruitment for him not being a wingback.
By the 18yo, do you mean Gil? He's done alright for a 20yo settling into a new league.
I'll give you Gollini, of course, and we may never know about Sarr.
Reggie and Royal were both decent signings in their positions, while Romero, Gil and Sarr could still turn out to be "really decent". I agree that we could/should have had a couple more -- we paid decent money for Lo Celso and Ndombele, after all.
As to the lower half teams, we all see the players who come in and look amazing, but we never talk about the ones that don't.