Marotta has been exceptional with his signings. Barzagli, Vidal, Lichtsteiner, Pirlo, Asamoah, Pogba, Tevez, Evra, Morata... 7 of our 11 starters weren't here when he arrived. And if you place Barza in place of Chiellini or Bonucci in a back 4, like a healthy and fit Barza would be, it's 8 of 11. He's built a CL final squad in 5 years, from consecutive 7th place finishing squads.
Conte deserves a lot of credit, of course. He was fantastic for instituting a winning mentality, at the very least in Serie A, a dominating mentality, and a relentless drive to succeed. Allegri came in and took the insanely high pressure edge of this mentality, which was necessary for Europe. Our team was too high strung in Europe under Conte, too much pressure, and they made a ridiculous number of mental errors, and couldn't finish chances at all. Allegri calmed their play down, and relieved the pressure quite a bit.
But the men behind it all are Marotta and Paratici. They have completely revolutionized our starting XI gradually over the last 4 summer mercatos, and turned a side devoid of quality into a CL final squad, with the quality to play multiple formations. They have also shown their worth in the ownership of the most promising young Italian talent in Italy with Berardi and Rugani. Not to mention having basically all the promising young attacking talent around on our books and making a profit on their sales. Immobile, Gabbia, Zaza..