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.