IMO we have to wait to see what the new blood brings to the table as well as Pirlo. That said we still need help up front especially with Dybala still sidelined.
It will be interesting to see what all 3 can bring to the table. If all 3 play really well then we are instantly a better team than we were in Sarri's last game.
So basically without any really big additions (unless Kulu or another addition does extremely well) I guess we will find out how much of a difference Pirlo will make compared to Sarri.