I agree with you. Manchester City have benefited greatly from Erling Haaland last season. Earlier in the season we saw Erling Haaland capable of scoring plenty of goals. We have seen great gameplay from Erling Haaland in every match at the start of the Champions League and Premier League. And he scored a lot of goals. Also, Erling Haaland's fitness is excellent. He admitted to very few injuries. However, we don't see many goals from Erling Haaland as Guardiola changed his match tactics at the start of the season. However, this resulted in Manchester City winning the Premier League and Champions League titles. In the last few Champions League matches we have seen opposition defenders only target Erling Haaland, making it easier for other City players to score.
There will be more exploits for Haaland at his very young age and even Mbappe. This will be the first Champions league where there is not Ronaldo and no Messi in the competition at the same time. They have the floor now to pursue and surpass the record set by both Messi and Ronaldo in the champions league. Currently of the two players, Haaland is in a better team to break the record with Manchester City than Mbappe who we do not yet know exactly the future club he will play for.