If they transfer Mbappe, the Haaland plan cannot come true this year because it is certain that they will offer a very high contract for Mbappe. Due to Mbappe's contract, they cannot make an astronomical offer to Manchester City and City will not send Haaland. In my opinion, Julian Alvarez could also be a good option for Madrid. Joselu is not very suitable for Madrid.
That's right, I also think they have prepared for a scenario like this, when they get one of the best young players available then they probably won't intend for another best young player. Moreover, I also didn't really hear about Real Madrid's interest in Haaland, and the news was only heard in passing and the news also came from a source that I don't think can be trusted at all.
Besides, will Manchester City let him go? I don't think so. And also from Haaland's side, it seems like he is very comfortable at Manchester City, so something that I think is a little impossible is now that Haaland is joining Real Madrid. Maybe in the future it could happen, but for now I don't think it's possible.
Real Madrid have a complete squad now, in fact I think they should look for players who can cover for Mbappe when he can't be played. That could be an option they can make to make the squad depth even better and they can also promote other young players.
They have alternatives for every player. Mbappe also has many backup alternatives. The only thing I observe now is that a finishing striker is required instead of Joselu. Maybe Dovbyk could be the right option. He had a successful season in Girona. On the other hand, Sörloth also had a successful season and he would be one of the players that would strengthen Real Madrid.