It's not about guessing their playing style, if you ask me, speaking generally about Juventus, their play style is much different compared to many other teams and they usually play defensively while they can have high-speed counterattacks and that's mostly because of the strong midfielders they have so they won't need to have the ball and ground under control whole they can use the counterattacks and but just using the chance they may have on the game they will win, from the games I saw that's what understood from the games.
Massimiliano Allegri must learn from Inter, Lille and Villareal how to beat Napoli. Even though two of those matches were friendly matches, I think Massimiliano Allegri will be able to learn something about Napoli's weaknesses. It's true that Napoli are difficult to beat because they are in the prime of form, but nothing is impossible.
Having 5 midfielders in this match will make the Juventus midfield even stronger. They need to dominate the midfield so that the movement of Napoli's forward players is hampered. Maybe this strategy will work, but Juventus can also take advantage of quick counter-attacks. Technically, I think Juventus will win.