I'm worried that if Napoli buys Lukaku, it won't match Napoli's expectations, and won't even have any impact on the team. In my opinion, it's much better to look for younger players whose stamina isn't a priority. If they force it, the big possibility is that Napoli will of course waste money on transfers. that happened, keeping Osimhen rather than having to sacrifice him just for an old player like Lukaku.
It seems like what you are saying makes much more sense than throwing away Osimhen who then brought Lukaku to Napoli because a player like Osimhen can still be relied on as the best spearhead in the team. Meanwhile, Lukaku still cannot be relied on as the best spearhead in the Napoli team, so it would be a good idea for Napoli not to throw away Osimhen for a player who is no longer young like Lukaku. But if Napoli can bring in Lukaku without throwing away Osimhen it would also be better because a team that has some of the best front line players will be much better although other players in the line also need to be considered.
Actually, Lukaku is quite great player and the bad opinion about him previously occurred because of decline in performance caused by the injury he suffered, look even though he is no longer young, Lukaku can still play well if he is with the right team.
If we evaluate it with Osimhen then we can clearly find the difference, Osimhen is still quite young and if the transfer happens only for Lukaku it will never be comparable but we can see it if Chelsea doesn't just give Lukaku but two players.
Moreover, Lukaku arrival in the Napoli squad was the wish of coach Antonio Conte, he wanted to strengthen the team with the presence of Lukaku, who was previously quite great player when he was playing with AS Roma.
But if everything could be done more easily, like Antonio Conte still being able to keep Osimhen and bring in Lukaku with purchase agreement, then that would be much better.
We see how this transfer-related problem is resolved, which has had quite lot of drama, news and attempts at talks between the two team that have been going on for some time but until now there hasn't really been an official agreement.