Even though it's not entirely true, I think we can't deny that Kevin de Bruyne's presence is also very influential for Manchester City. Kit can see from the several matches they played without Kevin de Bruyne, they were quite weak even though in the end Pep Guardiola was able to overcome this. When a team is used to a player, whether he likes it or not when that player is not there it makes little difference in the game.
However, overall I agree that Manchester City has an even squad, which helps them in rotating players which doesn't take longer to adjust. This is clearly an advantage that Manchester City has that other teams cannot easily have. Apart from that, they have coaches who understand the characteristics and abilities of each player, so it makes it easier for them to determine the strategy they will play in certain matches. It's not easy for a team to have an even squad like this, and Manchester City actually took a long time to create a team like this.
Manchester City have a fairly balanced squad and that's why they have been able to continue to be consistent until now despite playing in a busy schedule and losing some of their core players in crucial matches like now, but for De Bruyne, I think it is difficult to replace him as the most influential player in the squad, indeed Manchester City still have Kovacic to replace De Bruyne when injured, But if we look so far, Kovacic will not be able to reach the level of play shown by De Bruyne so far, and if you look at when De Bruyne was injured last October, without De Bruyne, Manchester City lost 3 times in a row, including against Arsenal at that time.
After the bad experience of losing De Bruyne last October, maybe Guardiola already has another strategy to beat every opponent without De Bruyne in the squad, regarding the game against Arsenal later regardless of whether De Bruyne plays or not in the game, I think Manchester City will still be the favorite to win, because after all at the moment Arsenal's level of play we cannot say at the same level as Manchester City even though Arsenal are now at the top Premier League standings.