None of our midfielders is suited for a CAM role.
Vidal is the most complete of our midfielders but deploying him as CAM would under-utilize his unmatched defensive skills. He scores an awful lot of goals from his current position and contributes defensively immensely. He should continue to play where he is best. Vidal also lacks the flair and dribbling skills that a world class CAM primarily depends on.
Pogba is too static for the CAM role too. Pogba is becoming a world class CM and his position shouldn't be tampered with. Giving him the regista role will undermine his attacking capabilities while having him play as CAM will undermine his ability to dictate play. He currently plays right where he needs to be.
Marchisio has showed glimpses of attacking prowess before but its far from what a world class CAM should provide and he completely lacks consistency. He is only consistent in the defensive phase of the game but hot & cold (with more of the latter) otherwise.
Pirlo is the player with the best vision and passing in the world but he is way too slow and lacks the penetrative dribbling that a CAM would normally provide. He has always been made for the Regista role and I haven't witnessed a single player that can compare to him in that role. At this age, he is still world class.
4-3-1-2 doesn't seem like a bad idea for me even if it lacks some width. It has to be some amazing CAM though for such narrow gameplan to consistently work. We'd also need a very good level from Tevez.
@Zacheryah
Conte's deployment of marchisio in an attacking role can be interpreted in two ways.
It can be understood as Conte believing he has the best attacking attributes of all our CMs (like you read it)
OR it can be understood as Conte choosing to play Vidal, Pirlo and Pogba in their best positions because having them there is of immense importance.
In other words, Conte might have found that a formation with Vidal, Pirlo & pogba as CMs and Marchisio as anything else is better to the team than having marchisio as a CM and sacrificing one of the 3. They had the privilege to start in their best position because of what they bring to the game from these positions. Marchisio got jerked around because he aint that special as a CM nor as anything else.