Can he? That is the real question. Surely he will have some hard time with the players and he may have issues that he may not do that great. Xabi did not manage some huge team before, which means that he never had this type of trouble, we need to be careful.
Each has a style of play that will be applied to the game. Obviously any player who is unable to adapt then he will not be used. Of course the coach has a big consideration on every decision. But I realize coaching star players will be more difficult than the collective of ordinary players. Maybe this will be Xabi's challenge in Madrid. If he manages to combine the team's collective play, with individual skills, it will be a deadly weapon. Madrid will be a good team.
The difficulty in coaching star players is that they tend to have inflated egos, always wanting to be the best, often playing selfishly, and being overconfident in their individual abilities to the point of neglecting teamwork. This is clearly a crucial task for a coach, as he must not only continually strengthen the depth of his squad, but also be able to defuse his players' egos and unite them as a unit. And the players must understand this too, because what is the point of individual achievements if the team continues to decline? They must understand that the club has paid them high salaries so they can play for the club, not just for their own careers.
Time is running out for Alonso; the season is about to start, and players are getting even less time to rest. Teamwork is paramount, and Alonso must quickly achieve it, creating the balance within the team he demonstrated during his time coaching Bayer Leverkusen.