take Matri for example. He was Cagliari's best scorer this season, and, AFAIK, after we bought him they didnt bring anyone else to replace him. What sense would it make for Cagliari to loan their best player for half a season for just 2 mil €? They lose their best striker when they're fighting to stay in Serie A, they dont get enough money to replace him. What exactly do they get out of the deal? Because if it's just a loan they'd lose him for half a season basically for free and get him back next season, without gaining anything. Now, they might be a small club, but I doubt their management is completely retarded.
Thats why the three above players are not real loans. They have been signed. The loans are just formal, for financial or other reasons, and Marotta has promised (or made a gentleman's agreement, whatever you want to call it) to buy them. The only way not to buy them would be for Marotta to break his čpromise given to the other clubs, and that wont happen.