it must take a long time for ruben amorim to reach the level of sir alex ferguson, because he has only just taken charge of manchester united, and it's too early for us to conclude that he can make such a leap immediately. the point is, if ruben amorim can improve the team's game structure and maintain consistent performance over the next few seasons, then he should be able to replicate the glory manchester united experienced under sir alex ferguson. but that’s only if he can, since it's not an easy task, given the immense pressure at manchester united and the consistently high expectations from season to season. he needs to be able to stay in that position and keep improving in order to achieve that.
Even Amorim stay in Manchester United for 26 seasons, I doubt he will get the same achievement as good as Sir Alex Ferguson. He's not able to manage the team, that's why the old players are still act the same like the previous manager.
I think it's because the old players didn't see the results during his management, hence the old players are no longer respect to him.
As long as the players do not respect the manager or are not in line with his strategy pattern, the team will not make any progress but the key is solid every direction from the manager, while the Ferguson Era is over now heading for a new era with Amorin who knows how to do it.
Sometimes with selfish players and stubborn coaches it makes the team crumble and I hope this red devils club doesn't suffer a bad fate like before.