Buffon, Chiellini, Barzagli and Higuain (when on form) are like that.
Its just that before we had most of the team being like that, with Bonucci, Alves, Evra, Vidal, Tevez, etc.
So now we seem a little softer in leadership.
Imagine if Dybala grew to have Tevez' drive on the pitch!
Sandro has to become that player too. He needs to step up to be a key member of the locker room.
Bernardeschi has that personality, for Viola he was a driving force not just because of skill. Once he becomes an important player for us we should see a leader in him.