I'm completely with you, John... but I completely misunderstood that OP was talking about using one futaba and one Hitec servo at the same time
(I guess I'm picky... I would never do that on elevators or ailerons ... but that's just me. )
you're absolutely right and my apologies to JollyPopper... I completely missed your point.
of course I had considered the single servo route, but since he already has the aircraft setup for dual elevator servos I didn't even add that to the equation
I also agree that dual servos (both rotating in the same direction) works when the servos are mounted offset (with the pushrod to elevator horn geometry being identical on both elevators)
I've got an Edge 540 set up exactly like that... but again since the servo's are already mounted...
I simply looked up the specs on the fly sky 9 TX and discovered it does have a dual elevator mix: simple, nothing extra to buy, adjust or fail.