Actually, those are bad examples and the truth is much better.
About centrebacks
Barzagli and Chiellini are just collecting the ball, and playing it shortly to Bonucci, a midfielder or a wingback. short simple passes. Chiellini sometimes storms forward if the opponents are sitting very deep, i dont mind.
Bonucci does a limited amount of "playmaking". Wich is usually reaching the wingbacks in a deeper position, playing over the opponents forwards and advanced midfielders.
Last year, we had Pirlo doing that. Bonucci doesnt do it that good, but he's no defensive liability
Midfield
...Is most of the issue. We lack general skill in the midfield with them injuries, so we find it hard to pass trough. And this makes Pogba stay deeper, so you get the gap. When Marchisio or Khedira returns, this problem will fix itself. Especially with marchisio we'll be having plenty of long passing range so we arent relying on Bonucci to do those tricky balls to the wingbacks
Wingbacks
Sandro has a significant forward going threat, and barely needs help in defending his side. He'll be making a whole lot of runs, and has the ability to do unexpected things, wich would catch the opponent surprised.
Cuadrado on the other side will need some help from the rcm or rcb, but well, i dont need to explain the big offensive threat he poses.
Both are amongst the best forward going wingbacks about.