The 3-5-2 is his optimal formation because he could operate more on the right side of the box. And we always had a wingback up beside him to stretch the defence as wide as possible. Because of that he had a lot more room to do damage.
Now he's playing more like a true SS but he's not good enough in build up to affect the game properly. He very rarely is finding space in between the lines, mostly because he can't really break the lines by himself. The best case scenario in build up is that he gets fouled, I find.
I'm still having a hard time finding a better comparison than David Villa. And what would it look like if you played David Villa as something like a CAM/SS hybrid? Probably the same as this.
It's tough to decide what to do with Dybala because the modern game uses only 1 striker nowadays. Of course, Barcelona's solution was to play Messi as a false 9 and have inside forwards who would score goals as wingers. To me, that is a solution for Dybala. I don't like him in the centre of the pitch. I like him always receiving the ball in the most dangerous areas and always looking to run in behind when he doesn't have the ball.
The midfield stuff should be left to someone else.