I my belief Manchester United should do this if it was feasible.
Need to sell in January or the summer transfer window: Victor Lindelöf, Harry Maguire, Mason Mount, Anthony Martial, Marcus Rashford, Casemiro, Raphaël Varane, Diogo Dalot, Antony, Tom Heaton, Jadon Sancho, Aaron Wan-Bissaka, Donny van de Beek, Jonny Evans, Brandon Williams & Scott McTominay.
Do not renew loan deal or buy in the summer: Sofyan Amrabat & Sergio Reguilón.
Keep: Altay Bayındır, Lisandro Martínez, Bruno Fernandes, Rasmus Højlund, Tyrell Malacia, Christian Eriksen, Amad Diallo, Alejandro Garnacho, Luke Shaw, André Onana, Facundo Pellistri, Kobbie Mainoo, Álvaro Fernández & Hannibal Mejbri.
In my opinion on humanity reasons we can't keep Mason Greenwood, but on football reasons only I would like keep him.
I think United should on any future signings or renew contracts from now on, should have lower basic wages with more performance rated bonuses in their contracts ie. goal bonus, assist bonus, clean sheet bonus and win bonus. Then maybe their performance will better in the future?