Whoever the player is, if they encounter a strong defense then they will struggle, not just Haaland. Looking at last season, when the club faced Mamchester City, their defense received special instructions to guard Haaland, and it worked a lot. But Guardiola's clever use of other players to be the second target after Haaland and proven when he struggles to find space because of tight guarding other players who create goals. Now here we can see good teamwork.
Guardiola has a lot of attacking players in the team and many of them have leadership qualities that allow them to take responsibility and therefore it is not so easy to restrain each of these players. Silva, De Bruyne, Gundogan (no longer in the team) could create the chance themselves and score a goal, the value of such players is very high and this allows City to have an advantage. Haaland is a very talented striker, Guardiola could see that in him.
That's the style of play that Guardiola has always employed, and he's been able to balance that by having some players who have more attacking ability, making it easier for him to rotate players whenever he needs to.
I haven't seen their defense this season, yes their strength has not been fully tested in the last 2 matches, in my opinion, we still need time to see it all, over time they will get stronger opponents and also better in terms of attack, which is now not fully seen.
The last match of the week is between Crytal Palace vs Arsenal. As a visiting club, Arsenal remains the favorite, but they also have to be very careful with Crstal Palace, the article they also have a good game yes even though in that match (week 1) they faced the promotion team.