I think the main problem was they changed too much of the coaching staff in one go. He got rid of top class coaches with experience of winning trophies and moulding top class players and bought in coaches who clearly were inferior. Tactically they have looked so poor this season, the players are used to working with top class coaches not who they have right now. They look very one dimensional and all their short comings are being brutally exposed.
Ferguson for all his faults knew his limitations and had no problems with letting people with more knowledge on that front make big calls and let them get on with things. Moyes I think is trying to be too hands on with everything. I don't think he has the tactical knowledge and needs to get better coaches in to guide him on that front. We have seen him go abroad to scout players & he wants to be involved on that front but look at the top class managers around, how often do they go around and scout players? There were rumours last summer that he wasn't comfortable signing some players because he hadn't seen enough of them himself. You need top class coaches & scouts around you to do that side of things, people you can trust and rely on. Ferguson knew the limitations of his squad and worked around that. He knew RvP & Rooney wouldn't work together as two strikers so he put RvP up top and Rooney behind him. You have to be able to adapt and Moyes hasn't been able to do that. I don't think he is a particularly bad manager but I think the powers above need to give him a nudge in the right direction as to how to run a club like Man Utd. He had little and limited resources at Everton but Man Utd he has all the resources he could ever need and has to be able to manage them all properly.