I agree with the majority view that this move is highly unlikely because Nuno will be in demand elsewhere.
That said, if our owners really did want to make a huge statement of belief in their approach then spending whatever it takes to get Nuno in would make massive sense. He would be absolutely perfect to mould a team and an overall approach that gets the best out of the random set of players we appear to have assembled.
I think there’d be few if any Blades who wouldn’t get on board if COH somehow pulled it off.