Yes, it's true that the Real Madrid squad is much better than the Leverkusen squad. If we looking at the current situation, Leverkusen is still quite stable with a squad that is usually at Leverkusen. What if Xabi Alonso trains Real Madrid, which has a more capable squad? of course Xabi Alonso will achieve success with Real Madrid and will probably get more than 1 title in 1 season, I really look forward to Xabi Alonso coaching a club like Real Madrid after all this will also make Xabi Alonso a successful coach if he trains a big club and is able to wins title.
A coach will be able to bring out the best potential from a club if the club has players and a style of play that suits the coach. That doesn't mean that if you are very great as a coach at a club, it doesn't necessarily mean that you will be even greater if you coach a club with higher quality players. There are many factors such as the coach's approach to the players or how the coach manages the existing squad to be able to play with the expected tactics. I agree that Xabi is a great young coach at the moment but if he were to coach Real Madrid then it would be a different challenge.
Managing real madrid would be far easier compared to the leverkusen. Didn't you know that Xabi was coming when Leverkusen was almost relegated last season? It was able coming back stronger than before by getting winstreak that has saved club from being relegated to the lower division.
I hope that someday, i can see xabi to join in the real madrid a coach for the club. It will be so good to see him joining as a new coach. Ancelloti's era will be gone. There's no reason to let ancellotti stay even longer.
He may be in here till next year.