Manchester city has been in consistent form in the champions league, they won all the teams in their group. Despite losing two matches in the premier league they are still in a favorable position and losing to Arsenal is not a prerequisite to see them as not being inform compared to last season and moreover, the leagues are still young so no teams performance can be judged a this early stage of the competition.
Manchester City must still be considered a serious opponent this season, both in the Champions League and in the Premier League because without even key players Manchester City is still able to provide very troublesome resistance to its opponents. Everyone can see how Arsenal won the match against Manchester City in the Premier League, even Arsenal was not able to score more goals in that match so they were only able to win with a few goals. So there is no reason to say that Manchester City is weak because so far Manchester City is still able to create good games in every match.
Manchester City are weak in comparison to last season when they won the league and the Champions League, but this season it is difficult for them to score goals easily since De Bruyne go to injury and I believe that Manchester City will not win the Premier League this season because they are not demonstrating that they can win the league when they play against Brighton, they win the match but struggle to score goals, Manchester City's lack of De Bruyne is causing them to play weak this season, if Manchester United defeats Manchester City this weekend, I will declare Manchester City to have completely lost form, In the Champions League group stage man-city is the best in the group stage because the clubs are weak, they did not join them with any big club in the group stage they have already qualified for the next round.