If Napoli is actually interested in defending the title successfully, they should actually think about bringing in players who will make the team strong. Defenders are obviously going to be very important for the team. Losing a really good player, like Min Jae Kim is obviously going to be big for a club that is defending the title.
There is no club that does not want to defend the championship title obtained last season. but, each team has different problems each season. Napoli, who have to change coaches and the arrival of new players, will make this season even more difficult to defend the title. Adapting this new strategy is sometimes more difficult for players to implement, this must be solved by the coach from the beginning.
For any championship club there going to be new problems every other season. The only way that the club is going to be one of the best is by fixing those problems.
Napoli, undeniably a formidable team, possesses the potential to extend their previous season's stellar performance and triumphantly safeguard their title. But as you said, there have been some changes in the team. New management and also some new players are going to have to start well this season. They will also have to be very consistent. Otherwise, they are not going to be able to win anything in my opinion. Honestly, I am not going to be sad if they finish in the second position, to be honest. But I want to see a great performance from Victor Osimhen.
With the recent changes at Napoli, it'll take a miracle for the them replicate their great performance of last season. The new manager and the new players would certainly have to work together for awhile to better understand themselves and find the best style of play that'll work for the team.
Defending a league title is considered to be harder than winning because other clubs in the league will be very much wary of the defending club.