Believe or not, Carlo Ancelotti is very smart tactician and he cans play well some players not on their real position, Rodrygo had impressive well last several season with Real Madrid and Carlo Ancelotti most of them put him as false nine for central forward although his real position as left or right winger side. I don't think not problem for Carlo Ancelotti if can reach agreement deal with Kylian Mbappe and he will put him as central forward and Vinicius Jr keep at his real position as left winger.
Luka Modric future have been released and Madrid not extend his contract so far, he will be free agent on the next season and his future can't speculated yet because that player not announce yet which one team become his challenge after leaving Real Madrid. Currently, Luka Modric performance not really bad and give him one year contract and he will back up as midfielder position.
Believe it or not, Benzema was the one who developed these two Brazilian wingers to perform very well with Real Madrid. the attack patterns they use are difficult for opponents to stop. the combination of player to player, forming a triangle pattern and that was one of Madrid's advantages when Benzema was still involved. At this time, Don Carlo changed his patterns and systems. because he does not have an ideal replacement in Benzema's position. and if in the end Mbappe joins Real Madrid, it could be that the pattern currently implemented will return to the old system of 4-3-3. yeah, Mbappe has no problem being placed as a central striker, because Don Carlo's strategy and pattern are a little easier to study. Let's just say Mbappe has joined Madrid, Vini Jr's position remains on the wing and so does Rodrygo. These three players will combine with fast playing patterns, especially when counter-attacking and Bellingam's position will return to being an attacking midfielder. well, this is just an assumption based on my personal assessment. which means, Mbappe's presence will not change the system implemented by Ancelotti. So, we wait for next summer regarding Mbappe. Talking about Luka Modric, I think he will end his tenure with Real Madrid. either hanging up his shoes, or maybe he's going to another league. BTW, I don't really know any new information regarding this player from Croatia. however, at the age of 38, it will be difficult for Modric to be involved with an elite team again. at best, Modric's final stopover to the Saudi Pro League.