Yes because i think immobile would do relatively well with the likes of mirko, giovinco, sanchez/suarez/jovetic next to him. He would be getting much better service here than he would at Genoa.
So yes, I'd rely on him as a 5th. Besides, we will need to raise funds anyways to improve the attack to get one of those 3 players...selling some players will be necessary. I'd be willing to give Boayke a chance too. Either one.