#2 4-4-2
Last season, we saw Barcelona using a similar formation with Lionel Messi and Luis Suarez up-front. Messi was the second striker who would use to drop back into the midfield, carry the ball and create space for Suarez just like a false nine.
Dybala, very similar player to Messi can take up the false nine role and thrive in it. He is well known for playing anywhere around the forward line with special emphasis on no.10 marauding and drifting in or out whenever needed Ronaldo will be open to more options in this setup against teams who would like to sit back. The wingers would provide much width which will stretch opposition's defenses.
In the World Cup, the former Manchester United man played a similar role with Goncalo Guedes. which helped him to store his stamina for crucial counter attacks. Dybala's run and through balls would unlock opposition's deep blocks.
This formation has just one flaw: not giving Pjanic the specialized role. Having a regista in a two-man midfield is not practical and would leave the backline vulnerable. Pjanic is arguably one of the best at what he does. Wasting a talent like that would not be recommended.