Montero was a beast (a slow one at that), but a beast nonetheless. He was aggressive (sometimes too aggressive) but usually fair
Ranocchia is nowhere near that level yet. I see where you are going with his potential, but like Mike said earlier, he might be mentally weak, lack confidence, has massive dips in concentration and form, and that can't all be down to the system or the fact that he is playing for a crappy club. If we are hellbent on getting rid of Vucinic, and he really wants to go to Inter, then a straight swap might be ok, but any substantial cash outlay is a waste.