I see you keep suggesting use him as a RB, but I haven't seen anything to make me think he'd do well there. It takes more than having a lot of stamina and aggression. Actually, as a defender he would have to be more disciplined in his positioning and would make less use of his aggression in closing down players, which is one of his few strengths.
I think that he is a good defensive mid, he has good tackles and stamina like you said BUT his offensive input is not good and is very random, his first touch is bad too.
I suggest him there because 1-It frees a spot on midfield for a more skilled one, and 2- He could channel his defensive duties and learn to be a good defender with training and mentoring.
It will not happen from day to night but since he knows how to tackle and has decent crossses on him, it could be tried. he has played there before, but it was a long long time ago.
What we would need for him would be only to keep the his position in a 4 man line and pass the ball to attackers or mids.
Wpuld be worth in a 433 or 4312. Not so sure in a 352...but we have other players for that like Alves and Cuadrado.
Mi idea od using a strictly defensive RB in sturaro, would be to bring cohesion and security to a more attacking formation than we use now.
Lets say we experiment next year, using more attacking midfilders, o using a forward line consisting of Pjaca-Higuain-Dybala...backed up by Marchisio witsel and pjanic...it would be safe to bring some balance in having someone like sturaro covering their backs and not going up.