Well I don't think anyone wants him to play as a target man 9 but as a false 9. We all agree that Dybala has to move around the pitch but he can do that as a #9. That's basically what he did vs. Bologna. They had 3 CBs marking no one. We had 7 midfielders and 90% possession. This is the way to use Dybala.
I want him as a false 9 because that means you have a minimum of 5 other midfielders behind him working in possession. So when he drops to collect the ball, we are outnumbering the opposition. So in that scenario, he has more space, more passing options.
When he plays as a CAM, the most players we can put into midfield is 5. So he can be marked.
That 3-5-2 vs. Bologna was perfect because both Ronaldo and Dybala came into midfield. We had 7 players there. You cannot possibly mark Dybala when there are 6 other players to mark (and still he missed half a dozen passes).
There is no reason that Dybala cannot play successfully with Ronaldo. Mandzukic is great in his own right but I don't think his highest level will trump the highest level of a Dybala/Ronaldo partnership.
The key is both Ronaldo/Dybala to stay off the CBs. The CBs will never follow them because they are scared of either of them attacking the space they vacate. We are guaranteed possession. And when you have so much possession, you will inevitably get scenarios where Dybala pops up with the ball in between the midfield and defensive lines. And that is where Max wants him to get the ball.