You may have to try different arms until you find two arms that put the arm on both servos at the same angle.
Geist, thanks for the suggestion, but I've tried a few different Hitec servo arms and even though one of the arms lines up at 90 degrees on one servo (with TX settings zerod out), the other is about one spline off from center. This bugs me because at least with futaba servo arms, they give you the option of trying 4 (or 5 on the smaller arms) different arms all on the same servo arm. Find the one that gets you the right geometry and cut the other ones off. However, I am using Hitec servos and need the longer arms. For $75/servo, I would think that the splines should line up at neutral when the arm is put on the servo. I've not had this problem with other dual ele planes in the past.
The mechanical setup may be off a little, as others have mentioned, but isn't it moot at this point? My point is, is that making sure the front of the ele halves are flush with the stab yields the current problem. Even if I mechanically adjust so that the linkages are equal, that may solve the problem of one ele being higher than the other in the back, but now they would be unequal in the front. ONe higher, one lower. If the fronts and back were both uneven, then yes, it would be very obvious that one of the linkages needs adjusting either mechanically or via sub trims/EPA.