So far Real Madrid performance under Xabi Alonso has been extraordinary, you can see it when they played in the Club World Cup. Xabi Alonso has made a huge difference to the Real Madrid squad, something that was never done in the Ancelotti era. Several young players began to show their passion after being given the trust to play, the scheme used by Alonso not only increased the team's strength, but can be relied on for the next few seasons.
He has had good beginnings with Real Madrid but perhaps he will have to maintain it in a long season. It is not matter if you can player well in one, two or ten or even twenty matches but eventually your team don't win any title. With a giant club like Real Madrid, title-less ending means severe failure.
Fran Garcia, Arda Guler, Gonzalo Garcia and Dean Huijsen are some of the young players who are long-term investments for Real Madrid. I also see Endrick potential as still not convincing enough to stay at Real Madrid, the presence of Gonzalo Garcia makes his position even more threatened, so it makes sense for Real Madrid to let him go on loan.
In Bayer Leverkusen, Xabi Alonso actually has proven his capability of management in general and grow up young players in particular. It seems he is very good at growing up young players and boosting their performances to higher levels by enlightening them on their ability of playing better and better over time.
It is still early to conclude that Xabi Alonso will continue this success in Real Madrid like it is his actual capability and not from pure luckiness. Anyway, soon we will know about it in a next season as Xabi Alonso will work with several young and potential players in Real Madrid.