Honestly playing Halaand had helped Man City though the team performance dropped this season, however the inclusion of Halaand in most their matches as their main striker is a threat to their opponent defense line though he might have few touches throughout the duration of the match and in most cases two of their opponent defenders often mark him thus creating chances for his other team mates, however I believe Guordiola made a mistake by selling Alvarez to Atletico Madrid had he stayed in Man City he would have helped the team this season just like in the absence of Halaand few seasons ago he always live up to expectations.
No one can say that Guardiola's decision was right. Julian Alvarez was a talented young player. His position in the XI's plans was mostly on the bench but he was unique as a backup player. Julian Alvarez could have done something great for Manchester City this season. As we can see from Alvarez's contribution to the team at Atletico Madrid. We can't blame Haaland for Manchester City's downfall in any way, because he is always identified by the opposing players and coaches and plans are made for him. Because the opposing team is too busy with Haaland, his teammates get some advantage to score goals.