Where is that documented?
We don't know and we cannot know how many deals can be attributed to either, but since he's higher in hierarchy he takes more credit and more blame as well. He makes the final calls.
If people are assuming that Parattici has more merit for some signings, I'll assume that some players that we didn't bring in the end, mediocrity like Pazzini, Gila, Diamanti, are Marotta's merit, since he halted those deals in the end.