if he manages to find a good team behind him and manages to turn his back on the goal I would say that Lukaku is the strongest attacker that Napoli can find at the moment and I must say that he also has a good specific weight and is very big therefore difficult to scoring, regarding the goals, the championship has just started, let's give it time
No doubt Lukaku is one of the experienced and strong striker around Europe currently. But he is not a striker a team can depend on because of his inconsistency. It will be safer to have another good striker to make the attack shape. He is not as fast and strong as he used to be and misses opportunities frequently. He is not in Napoli because of his quality but because of the cordial relationship he has with Antonio Conte. Napoli's coach believes the Belgian fits his style of play, so we have to give them time. He has already scored in his debut game, maybe more goals are on the way.
You have mentioned an important point. Lukaku is a talented player. But he cannot maintain the consistency of performance. In the last 2/3 seasons we have seen Lukaku perform well in few matches, but most of the matches he is unable to score or assist. Napoli, on the other hand, needed a striker who could score regularly. I doubt if Lukaku can meet Napoli's needs.
However, Lukaku spent the best part of his career under Antonio Conte. He was able to score a lot of goals with Inter Milan. And this team was coached by Conte. This is why Conte has wanted Lukaku in his squad ever since he arrived at Napoli. If CONte can use Lukaku properly then maybe we will see a better performance from Lukaku.