Word, I don't see the issue. If our forwards could finish, then we would've won alot of games using the 3-5-2 and nobody would be saying anything.
Napoli have also shown in Europe this year by dominating Chelsea, City and even Bayern(Unlucky to lose) and they have a terrible defence. Our defence baring the Catania game has never looked in trouble using 3 at the back. actually Bonucci looks miles better in the back three.