From my observers, in their 4 matches in this competition, City has experienced a decline in the quality of goals. City's expectations are too big given the record they have. Even though they carried out their matches smoothly, their goal productivity decreased greatly. except, during the Fulham match. The point is that since Pep has not re-applied his 3-2-4-1 formation pattern, there has been a change in their camp. Luckily Pep is a smart coach and has lots of tactics and strategies, he is now more inclined to implement a 4-2-3-1 system.
In the absence of De Bruyne, Stones, Pep adopted another option as the system he implemented. It's just that, when facing a slightly stronger team, City has to work hard to win the match. for example, when they played against Newcastle, City was only able to score one goal. However, every team that meets Manchester City must work hard to get good results.
Every season City has won the league this is what people say. You don't expect them to trash every team by 3-6 goals every match day. The other teams too came to win so they're not going to make it easy for Man City.
Liverpool looks like that the team that can give Man City the biggest challenge this season and even then don't win their games effortlessly.
The season just begun. Man City along with many other teams are still finding their rhythm. We know that Man City gets better as the season progresses so these performances are expected.
If they're able to somehow win in these uncomfortable situations imagine how they'll be when they start getting better and have De Bruyne back.