We think the Manchester City players have the same level of quality, they are capable of playing a role that fits the position Pep Guardiola has given him, Kevin De Bruyne is a general on the pitch who always shows his best class. Although Julian Alvarez is not as good as Erling Haaland in terms of goalscoring, he has also made a big contribution and from the previous two games so far he has scored two goals.
Alvarez does not have a body like Haaland and he does not have same skill set like Haaland has. They are different players and can contribute differently to the team. We should recognize good contribution and effort from Alvarez for Manchester City. He at least has good performances and did not waste scarce opportunities were given to him by a few matches missing Haaland. When Haaland returns, Alvarez will have to accept his position on bench and wait for other chances.
Well even though Haaland is the top scorer on Manchester City, it doesn't mean the other players was play bad. Don't forget they have Kevin De Bruyne which currently the best central midfielder player in this season, Phil Foden and Riyad Mahrez who have a good speed and accurate pass to support the center forward. As you can see in the last 2 matches of Manchester City, they let Alvarez to play, not Haaland and they won the 2 matches.
Kevin De Bruyne has different tasks in this season from Pep Guardiola. He does no longer play as same as in the past season with which he scored a lot of goals for Manchester City. With Haaland, Manchester City need more assists and dangerous key passes from De Bruyne. They no longer need too many goals from him.
Foden simply has one of his best season for Manchester City and it is helpful for him to get a ticket to World Cup.