There are only a few managers who can unite the egos of star players, maximize their potential, and achieve long term success. Real Madrid has star players in almost every position, and it's not an easy job to make them play collectively. Therefore, Xabi Alonso will certainly need to take a different approach in managing each of his star players so they can work well together. Of course, having many star players can sometimes only attract a lot of attention, not necessarily bring instant success.
Looking at the current conditions, I think Xabi only needs to really focus on improving Madrid's attack line, especially in terms of ego, because for the midfield or defense they can still be controlled but for the attack line, especially for Mbappe and Vini, it is clearly not an easy job.
Both of them have almost the same level of ego especially with the position that is actually the same for Vini and Mbappe clearly this is also a difficult job for Xabi to be able to create good chemistry for these two players.
But if in the end he succeeds in getting them to put their egos aside and switch to a collective game then I think Madrid will really be very well protected in terms of goal productivity because indeed these two players are very solid individually but quite bad when placed together in one club so far.