Xabi Alonso has proven that he can build a team with even strengths across all departments when he was coach of Leverkusen, so I think he could do the same thing again with Real Madrid in the future.
At this point, we can't make any judgments because Xabi Alonso is new to Real Madrid and still needs time to adapt.
Regardless of who Xabi Alonso chooses, I'm quite optimistic that Xabi Alonso can make Real Madrid even better.
And it's also important to remember that Real Madrid are the Champions League champions, so they must remain a force to be reckoned with no matter the circumstances.
From the outcome of the games in the FIFA World Club, it is obvious that Xabi Alonso has a difficult task ahead. Carlo Ancelotti's shoes might be too big for Xabi for the initial period until he gets used to the players at Real. Carlo had a big influence over the player because of his age and experience, but Alonso would have to build respect.
As regards the transfer of Rodrygo, my take is that he should leave Santiago Bernabéu if he wants to play consistently. With the array of stars Real Madrid has especially in the attack, the Brazilian would have to endure a rotational performance. There are many other top clubs that can guarantee him a permanent spot in the club.