I'd say let's take a left back , an SS and a winger.
And use either the 3-5-2 or the 4-3-3 , depending on the match.
3-5-2 Buffon, Barza, Chiello, Bonucci , Licht , Asa ( Licht and Asa not ideal for 3-5-2 just decent ) , 3 midfielders , and SS + Llorente
4-3-3 Buffon, Barza, Chiello, Licht, Left Back , 3 midfielders , LLorente, Winger and SS in a more fluid role.
Padoin, Peluso, Giaccherini, Caceres the extras in defence and midfield.
Vuc, Gio and maybe Quags ( ? ) the extras up front. Pepe ( ? )
Isla i dont know , I am a bit disappointed.
Marrone it's the big question. The midfield is overcrowded. Could he help us as a defender? I really like the kid though, he is talented.
As for the 3 midfielders there are like 38 games for serie A, lets say 8 games for Champions League if we pass one round ( possible ) , like 3 or 4 games for coppa Italia and 1 for super cup. With a decent rotation and not letting Pirlo take all the fucking games in all the competitions ( not judging , but he really shouldnt play ALL the games , it's impossible to handle that at his age ) I say we can keep Pirlo, Vidal , Marchi , Pogba AND Asamoah pretty happy , at least for one more season.
All in all something like Buffon, Storari , Leali (?) , Barza, Chiello, Bonbon, Caceres , Peluso, Licht, Left back , Padoin, Giacch, Asamoah , Pirlo , Vidal , Marchisio, Pogba , SS, Winger , Llorente, Gio , Vuc , Quags ( ? )
3-6-1 it's not the solution , me thinks.