I've no idea whatsoever what Juve is thinking signing a 33-year-old Ronaldo at this stage of his career. Lucky if Ronaldo gives them one good season.
Add to this that Ronaldo is a selfish prick easily capable of upsetting team chemistry - and you've got a potential disaster just waiting to happen.
They have plenty of oldies though and it works just fine in Italy. They just extended Chiellini and Barzagli too.