A big difficulty is that we've seen a lot of very good players go to United and eventually go rotten.
If we are including Pogba, since 2014... Rojo, Shaw, Di Maria, Schweinsteiger, Schneiderlin, Depay, Darmian, Martial, Bailly, Mkhitaryan, Ibrahimovic, Sanchez, Lukaku, Lindelof, Dalot, Fred, Wan-Bissaka, James, Maguire, van de Beek, Telles, and Varane (and Rashford eventually) are a huge list of players that not only failed to live up to their hype, but all ended up being mostly bad whilst at United. And it's been the same with their managers too!
That club is a graveyard. It is virtually impossible to fairly assess anything out of United as it's such a toxic cesspit.