Been thinking about how we seem to be so out of sorts this season (although our 'out of sorts' is still a lot better than most other teams' 'decent'). I think you can tie it into the debate around Grealish.
It seems to me that Pep's tryimg to play the same 4-3-3 (or more precisely a 3-2-2-3) we played with Sané and Sterling. But we don't have those two players so he's tried to shoehorn Grealish and (to a lesser degree) Mahrez & Foden into a system that simply doesn't make best use of their abilities.
It's alright saying Grealish is a 'failure' but he's not being played in the same role he played at Villa, where he operated more centrally just behind the front players, be that as an 8 or 10. He wasn't a wide player. You could probably find posts of mine on here that praised Grealish as a perfect Pep player when he was at Villa. He used the so-called half-spaces brilliantly so I wasn't surprised when we signed him.
But Pep's used him (and others) as square pegs in round holes in this system we play. It's like trying to play a guitar with a violin bow. You'll get a tune out of it but it won't sound right.
We need to go to a 4-1-3-2 (or 3-2-3-2 in possession) with Haaland and Alvarez (or Mahrez) up front, with KDB, Foden and Grealish (or Bernardo, Gundogan, Palmer) as the three behind them.
For me, that formation maximises our strengths. It would surprise me if Foden, Cancelo and Walker aren't being played because they're unhappy with what they're being asked to do, and it's showing.