When compared head to head based on both of the team's record when playing against each other, we have that from 4 matches, Real Madrid won 3 and had one draw, while Napoli has 0 matches won against Real Madrid, 3 losses, and a draw. Moreover, in this record Real Madrid has scored 12 goals against Napoli while Napoli has only scored 5 goals against Real Madrid. In addition, Real Madrid has 14 titles in this competition, while Napoli has 0. Based on these and taking into account that Real Madrid has the best team, I believe that Real Madrid will win against Napoli for the 2023-24 UEFA Champions League Group Stage.

https://www.uefa.com/uefachampionsleague/history/h2h/50051/50136/

Real Madrid-Napoli Head-to-head | History | UEFA Champions League

Official UEFA Champions League history. Season-by-season guide, extensive all-time stats, plus video highlights of every final to date