You didn't put it into consideration that Real Madrid aren't complete right now, Militao, Vinicious, Carvahal, even Courtois isn't in good shape but they still want to risk him in their next game because the team will have to be mixed up so they can play very well. Real Madrid are great team in Laliga but my bet are on Barcelona from the way they have turn out this season, they are incredibe in everything they are doing, only luck is going to save Real Madrid.
A big team like Madrid should not be worried just because some of their players were injured because every football fan will expect Madrid ti have squad depth, and the team should not be in bad shape because of absence of some players; therefore, if they lose in this El Classico this time, player's injury should not be an excuse for them because Barcelina's squad is also incomplete due to inkjury.
The worst that is going to happen is Real Madrid might do a draw in this match if Mbape and Rodrigo are position as winger and Bellingham as striker, I know this formation looks weird but this is the best I think Anceloti can do to confuse Hansi Flick and also make sure Rudiger swallow Lewandowski, they shouldn't sleep on Lamine Yamal too, that way they will game but will be draw.
As you have mentioned, Barcelona have a lot of talented players that can cause problem for Real Madrid just as Madrid have Mbappe to be a threat to Barcelona's defense.
I am not seen a big difference in these two teams, both of them have all it takes to win the game, so I don't expect any excuse should come from fans of either of the two teams; any team that win will have three points and keeps another record.