The Milan team is able to show its great abilities time and time again. But I don't think it will have any adverse effect on their team if they played a bad match in the middle. In the next matches, the team will play exactly like before and ensure victory in a big way.
They potentially have the best team in the league, value-wise
but often having the best team doesn't mean knowing how to manage them or knowing how to make them play well together
It's not trivial or easy, but Milan have other problems in my opinion.
As I said before, if Milan can still hold a draw or beat Napoli in the Europa League, then Milan has a very appropriate way to fight Napoli and can be called a counter. So, with Milan's two consecutive wins to beat Napoli, then surely Milan really managed to beat Napoli, meanwhile I still don't believe Milan is capable of doing that.
But even so, Napoli's position in Serie A will of course still be safe, because I don't think all teams can beat Napoli in Serie A. Also, even though Milan managed to beat Napoli even with clean sheets, of course Napoli will make even better efforts for the next match.