doubt we needed to balance the books, and if yes, there were other ways. as for Milan, they wanted Higgy and Bonucci wanted here, there were ways to do this without Mattia.
Hasn't this already been addressed publicly by our management? That the goal was to avoid a loss on Higuain and that was why accepted a payed loan for a 90mil player because the cost of the loan was exactly what we needed to achieve that goal? That we couldn't find an acceptable bid for the full rights of the player and Milan weren't down for the deal without Caldara to replace Bonucci?
Most importantly if our goal is to win a Champions League with this cycle of players then the time is right now. When Ronaldo is still in his prime (despite his GOATness impossible to predict how a 33 y/o attacker will look in a year or two) and some of the usual giants (Real, Bayern, Barca) seem to be in a period of transition.
To restate, in between all the whining over Caldara our management did address the motivations behind this transfer publicly, despite a bunch of Tuzzers not liking it the reasoning is perfectly solid, if we want to actually win a Champions League trophy the time is now and Bonucci offers more now than Caldara does in the short term.
Bonucci's errors sure do look embarrasing for a player of his level but the net gain is positive. We had no Bonucci, instead Chiellini - Benatia for large parts of last season and how did we look defensively? Like a joke for large parts of the seaon because our defense was under constant pressure because we couldn't stop turning the ball over in silly situations, even against vastly inferior opposition. Defending is a team effort and Bonucci is a defensive upgrade if his ability on the ball very much cuts down the chances opposing teams have to put that defense under pressure.