In my opinion, it was a game of two managers, one with a clear way of playing, the other, trying to adapt to the one with a plan, but the thing is, Mourinho didn't even clearly try to adapt to City, he was torn between doing it his way (would have been perceived as negative) or doing it "the United way" and that was the principal reason we lost the game, we didn't look like a team that had a clear plan, this was even more evident in the second half when we started playing long balls, something LVG was slaughtered for. I don't want a Manchester United team to resort to long balls in any game, for any reason.
We lacked organization, energy and cohesion, and the players he picked to replace the previous 2 starters didn't help matters. Bizzare to start Mhiki after the injury he suffered, Mata was available, can handle pressing, it was also a stupid decision to bench Martial and not put Rashford in his place, Lingard should not start in place of Martial under any circumstance. Rashford in place of Martial would have been a better decision in my opinion.
Then, going forward, I still think we're better off with 3 midfielders, all our midfielders are better suited to that system, there's no point signing a player for £90m and forcing him to do something he has never done in his career, this has the feeling of another LVG-Di Maria situation, of course, Pogba should have done better, as the formation is not an excuse for going missing in a game of this magnitude. Going forward, we have to do 4-3-3. If we're going to insist on playing Pogba in a midfield 2, his partner has to be someone that can control a game, with Fellaini (he was good again) & Pogba, we can't do that, and against big teams, it'll cost you, it cost us today.
Having said all that, there's still 34 games to go, and we're going to challenge, but there's a lot of work to do, and players have to step it up.