I wouldn't have thought Minozzi is much smaller than WLR (S Hogg??). Physicality (size) shouldn't be a consideration for a 15. They aren't there to make tackle busting bursts into the line or smash back forwards in the defensive line.
Good under the high ball, ability to read the flow of the game, decent speed (again not a pre-requisite, neither Brown or Goode are speedsters) and to be able to make last ditch, corner flagging tackles (is E Daly able to do that at 15??).
There has been a drop in Italian signings to the EPL recently. The tendancy seems to be for good Italian players to go to France, so its interesting he chose the EPL and Wasps