Seeing from Rome's game, which is still unstable, even though it's quite good, I don't think this is a serious problem for Napoli.
They are filled with quite high ambitions, especially now that they have managed to run alone with a 12-point lead in the title race, this is clearly something good enough.
If Napoli still can do their match as great as usual, I am sure enough that Napoli will have a higher chance of winning from Rome, moreover, they are playing at home This will add to their motivation to do their best for their fans and everybody there. As you said, Napoli also has some experience facing big clubs and can manage it very well, with solid performance from every line. We can say that Napoli always gives their best in every match.
I think for now there is no need to doubt something like that, especially with Roma's current performance, even though they are one of the strongest teams, it won't go well for them and I'm pretty sure about that with their condition, which has no problem with current player.
On the other hand, Rome has high motivation after defeating Milan with big scores previously by winning 4-0, I am sure that this will add to their motivation and spirit to do the same thing when against Napoli. But here, Napoli is exactly different from Milan and we also know that Rome's performance is sometimes not consistent, so this may be changing.
Wait, it seems you are wrong in this case maybe what you mean is Lazio not Rome when referring to the 4-0 win.
Roma in the previous 2 matches excelled quite well when they faced Fiorentina and Spezia with a score of 2-0.