If the news about Manchester City being interested in Erling Haaland is true, then it is making me excited already. However they aren't going to be the only team to offer a deal for him of course. But if Manchester City also join this race, they can be one of the closest teams to sign a deal with him. But Real Madrid still could have the most advantage.
Its hard to say about Madrid. I think it would be either Mbappe or Haaland but not both. With Mbappe being close to sign for Madrid in the summer I don't think they would go after Haaland then. But if PSG manages to extend Mbappe's contract or some other team (other than Madrid) gets Mbappe then in that case I think its possible that they would go after Haaland.
Haaland to City seems like a very good news but I think he is gonna honour his contract with Dortmund for now and Dortmund is with stance that they don't want to sell Norwegian striker so unless City offers them a very good deal I don't think Dortmund are gonna let him go.