Dual-servo elevator linkage geometry
Regardless of where the pushrod is located, if one servo arm is up, and the other is down, there is going to be SOME (even if minimal) difference in throw. I'm not even saying that it will be enough to make a difference. I'm just saying if you really want it to be the "Best" way of doing it (Andy DID ask what the best way was), then you want to have both servo arms facing the same way.