I can't fault Ole for trying a diamond or 4222 against Arsenal seem as we hammered Leipzig with something similar, and everyone was getting excited that perhaps Ole has finally cracked the Pogba puzzle. But we all realized a few days later that Pogba is a not a PL level midfielder. He's like a Veron, he needs too much time on the ball, doesn't have the defensive intensity/focus required and he is not cut out for the PL, even though he can still be an important squad player here for when Bruno needs a rest.
The biggest worry is that it appears Ole completely botched the transfer window. We can all blame Ed for Cavani which is a player I doubt Ole wanted, but Ole going for Van De Beek instead of Partey now looks like madness, unless VDB suddenly becomes a major first XI player which is looking unlikely.
If it indeed turns out that a poor transfer window leads to more poor performances in the coming games, then that's unforgivable and Ole will have to get the boot. I'd give Ole one final chance to turn it around but one more result like the Arsenal result and he should get the boot.