Even if, for arguments sake, I agree that Chiellini isn't too aggressive, that doesn't solve the problem.
The best CB pairings have one CB who wants to move forward and attack the ball, and one player who wants to drop off and act as sweeper.
Both Chiellini and Mexes want to go forward attack the ball, which can lead to imbalance.
And 99% of the time, the guys who are good at organising and controlling a back line are the sweeper types because it is easier to see the pitch properly from there.
If you have two really great defenders who are similar, they will find a way to work together, but I don't consider either Chiellini or Mexes to be particularly intelligent footballers.
Well said.
This is also the reason why every great-legendary pairing of CB's is a combination of Libero-Stopper (Scirea-Gentile, Baresi-Maldini/Costacurta/Ferri, Montero-Ferrara, Nesta-Cannavaro).
That's why I'm a bit dissapointed with Bonucci signing. Not necessarily because he's bad (although I'm not rate him that much). It's just that I'd rather we bet on Ranocchia, because not only he's a sweeper, but also IMO have a bigger margin of improvement than Bonucci's, and perhaps, cheaper.
The other option is Zapata (judging from his playing time last season, I think he's finally overcome his niggling injuries). That said, this one is going to be difficult since Pozzo has already loaned another of his CB, Coda to Bari.
Realistically, who do you suggest?
Oh, Lugano is good but I don't think Marotta would be prepared to pay his big wage. Either way, I'd pass him.