Something to do with the tactics and setup, what do you think?
Definitely, also DDG's old frailty of staying on his line has comeback to haunt him. Maguire and Lindelöf still don't realise David never, ever comes more than a metre off his line, hence whenever they forget this and the opponent puts in the right kind of cross, usually from a dead ball situation, then we are 'undone'.
There is no Carrick to patrol in front of the back four, although in his first season Matic did this admirably, but his fitness, especially his speed has diminished, and though he tries to make up for this through experience and his anticipation, he still needs
young legs around him.
Shaw whilst offering something going forward, still makes the same defensive mistakes as he did when he arrived and there is now no Mourinho to run up and down the touchline to tell him where he should be. When Shaw is not where he should be we are exposed down the left side, especially when McTominay, (or even Pogba) are absent.
Against Arsenal the problem was on our right flank, with both Kolasinac and Aubameyang driving down on AWB, one pulling him out of position whilst the other played through. James didn't seem to realise he had to give some cover and when he did Kolasinac was too strong for him. Fred and Matic were struggling manfully in midfield, and couldn't get across to help, but the truth was Ole misjudged the tactics Arsenal would use, their attacking set up seem to puzzle us, although bearing in mind they had to win the game to avoid sinking further towards relegation zone, it should not have been a surprise.
I like Ole and think he will be successful, but it cannot blind us to the fact he still has a lot to learn as a manager, in terms of set up and tactics and definitely needs the help of a DoF.