Ferguson is not the last good coach for Man U... It's just that the club management hasn't been able to find a really good coach yet... Man U have really good players and superstars, but without quality club management they will never get good results... The situation reminds me of Barcelona when they played horribly, but after Xavi came in, they were able to finish second in the league... About the same decision is needed for Man U...
No coach after Sir Alex Ferguson have enjoyed the support and backing the club gave the veteran. I thought Jose Mourinho would have been great and to be fair, he did great. He's the best Manchester United got after Ferguson but the club and fans failed to back him when they needed to. They chose to back players that were clearly underperforming.
Manchester United panicked about his condition at that time, but if they had a little patience, Mourinho could be the right successor for Alex Ferguson. Mourinho can't be considered a failure at Manchester United, he has won the title with Manchester United, the Manchester United side can't see with their eyes open to Mourinho's performance, sacking Mourinho is the biggest mistake that Manchester United have ever made, because until now they seem to have a curse. Every coach who is brought to Old Trafford, always fails to improve Manchester United's performance, even though he has brought Ronaldo home, Manchester United's performance is still far from what was expected.