I think about Halland, it's as simple as it looks, just from the naked eye.
1. He's less involved in a game. On derby day he really tried to get involved, who has his touches numbers for yesterday game? Against Bournemouth, he had only 8 touches, 2 of them were completed.. - this means the team defends with 9 men, control the game with 9 men, progress the ball with 9 men ; which = to more work on others. This is confirmed by if he doesn't score city struggle alot, and city have conceded alot of chances & goals ( they defend as 9 men)
2. He stays up on the pitch. As a goal poacher he will tend to stay higher up the pitch, on derby day he really tried to come deep for the ball. Even Pep said after the game he wanted Halland to have more connection with his teammates.
What staying up the pitch does is it creates a bigger space between him and his teammates.( Ole biggest flaw in 2022, brought by Ronaldo to the team).
In turn this makes the work to create chances more harder, as you need more precise passes, crosses and you have to run more and cover more pitch size YET HE DOESN'T DO all this things his teammates have to do more to bring ball to him.
United fans can really understand it, because of Ronaldo effect, he scored all the goals in 2022 but the team scored fewer goals in general. Bruno, Rashford, Martial, Greenwood goal number went south when Ronaldo came. In City Bernado, Kdb, Gundugan, goals dried up.
City at the peak of it's powers had an EPL season when goals from Sterling 18, Aguero 21, Sane 10, Kdb 8, Bernado 6, Silva 9, Jesus 13, Fernadinho 5, Gundugan 4.
Now after Halland 21 goals it's Foden with 7 then Kdb with 3. Foden 3 goals were against United in October.
So Halland will score goals, because City will pin teams to their half alot, so the whole 10 players will be near each other, near opposition box, length of passes will be small, defensive work will be manageable as it's congested. ( Same problem now ails Liverpool, all it's games are stretched, everyone on the pitch in stretched, from defense, midfield, attack).
You know why yesterday United were so good in first half, we were so close to each other, simple passes would bypass City through midfield, yet we can all agree we were not even on gear 2 attacking wise first half. ( Unfit Martial, one leg Rashford, Bruno winger).
It's also Arsenal biggest weapon, attack as a team and defend as a team, and all in waves and packs.
So Pep has to find a way to involve Halland more, that's all. Does Halland has the skillset to be involved and still score many goals we will have to see