Over the last few years we have stagnated in most positions. I haven’t seen any goalkeepers, centerbacks, full back, wingers or center midfielders really get better than they were to begin with.
I do think though that Lukaku, Niasse, Tosun (though only a short time), Calvert-Lewin have all improved over the last few years.
Whether Ferguson has anything to do with that I have no idea but it seems to be the only position I’ve seen notable progression and development in and I remember specifically Lukaku talking about his work with Ferguson being great and DCL as well (as well as with Rooney).
...I’ve certainly not seen him ruin any players the way Koeman and Allardyce seemed to with our defence and midfield so hard to have an issue