It could be said that Spalleti is a more suitable coach for Napoli but unfortunately Spalleti couldn't stay at Napoli for a long time. Maybe if Spalleti was still at the Napoli club it seems like Napoli is still in stable performance even though it won't be easy to defend the title but at least Napoli might not experience a decline like this season and may not experience so many difficulties because Spalleti can create a strategy that suits the Napoli players. However, unfortunately Spalleti left and the coach who replaced him has not been able to provide significant improvements.
Yes, currently Napoli is struggling to occupy the top 4 position so that next season Napoli can compete again in the Champions League but it seems that Napoli is having difficulty reaching the top 4 with its unstable performance while Fiorentina and Bologna are also try hard to enter the same ranking, we'll see just whether Napoli can occupy the top 4 position with his current condition, maybe if Napoli is able to improve the team's performance and appear more impressive, Napoli still has a chance to occupy the top 4 position this season.
Even I have to be agreed with you about this all but still this all is imagination because there is no doubt Spalleti done impressive job and achieve title after years with the leaves this job on high note and now doing Italian national duty, but we can be having same things with him which are hurting Napoli, and now they are down with poor performance and inconsistency as well now they are going to face AS Roma which is also badly down and having not fair chance for jumping into top four.
In last five game, Napoli fail to score any goal in three which is surely big problem for them, and they are surely needed to fix this if they want to have some honourable end of this season otherwise look like they could be badly down into this season, and then we will have no positive things for some years again.