Xabi seems to adjust the formation used with the available players. Xabi in Leverkusen more often uses 3 defenders and 4 midfielders, which makes Leverkusen's type of game with dominant ball possession.
But it seems a different pattern is applied to Madrid, who have stronger players in the attacking game pattern. We have not seen how effective Xabi's method will be applied for next season. But hopefully, there will be no problems with the players and the playing style designed by Xabi.
So after Barcelona had had so many disastrous seasons, he came, if i am not mistaken, Xabi and convinced the management to go into debt to rebuild the team and it worked, if i am not mistaken, even if partially.
I think he has a good vision although maybe Flick is better