Osimhen's contribution to Napoli is truly extraordinary and there is no doubt as seen last season when Napoli won the title in Serie A. However, this season Napoli still have to fight hard for this and at the start of next week or more precisely at the beginning of the month In the future, Napoli will also face quite a tough opponent in the Champions League, namely Real Madrid, so this means that Napoli may have a little difficulty getting a win even though the match takes place at their own home.
Maybe what you mean is that at the beginning of next month the meeting between Napoli and Madrid, both of them have already got three points, of course Napoli will find it difficult to face Madrid later, as we know that Madrid is the club that is always at the top in the CL, but it is also possible that if Napoli plays Defending will also be difficult for Madrid to get three points in the match.
I think playing as hosts, Napoli should be able to win, even if they win narrowly, they can at least pocket three points and maintain their position at the top of Group C, but if you say that these two clubs are playing well in the domestic league, even so, Madrid will always be at the top. superior even though playing as guests they can definitely give Napoli a surprise.
Napoli and Real Madrid currently surely at the same level but here we have to remember that Real Madrid is having love affair with Champions League which is mostly given them good advantage in all games against all opponents and after losing against Atlético Madrid they are doing good and Napoli is also having on and off the field issues which are going to hurt them, but this match is going to be not easy for the both teams with I am favoring draw/away because they are much better and competitive.
Even there is no doubt about Napoli and Victor Osimhen performance, but relatively they are facing some issues in this new season which is clearly giving them below in performance, and they are also not good as they were in last season which is surely not helpful for them.