The issue is the decision not to wait. With Ole as temporary manager, the team were running, they were working, and they were starting to click.
Two things:-
1) Since his permanent appointment, a lot of those same players have downed tools again.
2) Ole's tactics have actually become more cautious and less effective the longer he's been at the club. When he arrived, he said Rashford was his centre forward, and he put Pogba 20 yards further up the pitch.
Unsurprisingly, they looked threatening and Pogba was winning games on his own within 60 minutes. I'm not sure why the team set-up has changed, when that approach was clearly working so well.