Culture doesn’t change. It’s like under SAF, the players changed but the culture remained the same. Because new players would inherit the existing culture of the club.
What United need is a couple of players who hate losing, have very strong personalities and will basically force their identity/ethos onto other players
You raise a good point in the first part of that 2nd paragraph. For now, what United need is to win football matches again. By hook or by crook.
Post Moyes, there has been too much talk of philosophies and identities. Football has been made overly complicated by nerds across the board. It's a short term game and you're never getting the time to bring massive changes all at once.
Short term gains on the pitch should run parallel with wider changes off the pitch. Hire better scouts. Hire better negotiators. Hire better people in the academy that can help with players personal development in addition to their development as a player. Hire a manager, that in the short term, can work with the tools that he has at his disposal in the most effective manner. If you have better people working in the background then the manager will eventually have a better pool of players. If the manager isn't working out, change it.
The manager should never be in a position where he finishes 8 or 9 places below the previous manager and essentially blames the squad for not being able to play the system. If you can't at least maintain what happened before, you shouldn't be in the job. If you have to bin your philosophy for a few months to make sure we don't finish the season in 17th place on 39 points, great. Just fecking win some matches.
Granted there should be a longer term goal in mind and you need to have a manager in mind that can take us to actually have sustained success, just make sure there's already a platform in place because you've succeeded in the very basics initially.
Mourinho wouldn't have been able to succeed at Chelsea if Ranieri hadn't got them back into the Champions League.
Guardiola wouldn't have had the same success at city without the early title wins of Mancini and Pellegrini. The later being one of the most successful stop gap managers ever once they realised Guardiola was going to Bayern in 2013. He came in, won them a title, kept them in the Champions League places then was binned once their main man was available. Brutal but it was incredibly successful.