If Thiago Silva was taking the penalties for Milan, then they too wouldn't have had a striker in that list. But they were still gonna be, by far, the best attacking team in the league with 37 goals and with an attack that spreads terror. An attack that wouldn't have needed Tevez with Cassano available.
I'm just saying that the list doesn't tell the whole story. In Juve's case it indeed confirms what we know - lack of attacking power, but in Milan's case it gives a wrong picture.