Marchisio and Dybala are obviously our most important players. If one of them would suffer an injury it would have huge impact on our results.
I've been a bit sceptical about Beppe splashing 40m on a kid with one season as Serie A starter as Tevez replacement, but what a great decision it was. The Alex Sandro deal was brilliant as well. Shows he is not a penny pincher, but simply a financially very reasonable manager.
He showed multiple times he's brilliant when "opportunities" arise, but with the Morata (if he manages keeping him here), Dybala and Alex Sandro deals he showed that he can land "big transfers" as well, at least in the young player section.
Next higher step would be transfering a big player in his prime, but I'm not sure this is possible with our financial firepower. PL clubs, Barcelona, Madrid and PSG are simply on a whole other level. But with a little luck and the proper situation I'm sure he could snatch up someone like Isco, Götze, Gündoğan, etc.