No doubt Man U has some issues with not knowing the style of team they want to be and not buying players to fit a style. They seem to just buy what is hot. Chelsea and Man U seem to have similar issues at this time with both spending lots of money on random players and refusing to allow their Manager the time to build the team he wants. At some point you just have to find the right guy and give him 3 or so years to build a team.
I'm not sure that ETH fit at Man U or in the EPL for that matter, but no manager is going to succeed unless you give him a few years to get the players he needs to run the system he wants. Problem is that I'm not sure that Chelsea or Man U can commit to a several year rebuild given their fan bases. Arsenal managed to pull it off, but likely only because Arteta and Edu were former Arsenal players and Arteta managed to win an FA Cup in his first year. That and they basically hit rock bottom for a team their size before the rebuild.
I do find it amusing that Chelsea is apparently thinking of trading Poch for Mourinho. Meet the new boss, same as the old boss. I mean they just seem so similar except Mourinho is so much more demanding of the club and harder to work with.