I understand what you are saying about the surface size. You must take that into consideration. But you also must take into consideration what the surfaces do. I mentioned before about the elevators changing the direction of the plane and the ailerons do not. Look at it this way. How many G's are applied to the plane when you do a high speed aileron roll with 45Degrees of deflection. None, Zip, Zilch, NADA. Now, at that same speed pull full up elevator with 45 degrees of deflection. How many G's are applied. As many as 12 or more. This would take considerably more torque from the servo regardless of the size of the surface (unless you are talking huge ailerons and tiny, tiny elevators, which wont be the case in a 3-D plane). In fact, I would put more emphasis on the elevator than the rudder on most planes. In fact I cant name one plane that the rudder is as powerful as the elevator. I know many of you will disagree, and I will change my point of view if I'm proven otherwise. But since we are talking about split elevators and to prevent a war, I still say Rudder, then Elevator, then Ailerons.