I agree with Jaka, you don't need servo arm and control horns at same diameter. You don't even need the holes on the control horn to line up with the hinge line. It is common, to offset these to gain mechanical advantage and/or to ensure crisp neutral by causing the non-working line to go very slightly slack at heavy deflection. I almost always offset and/or mech advantage my rudder pull/pulls.

I also agree than on small foamies, it is easier to setup and maintain push/pull setups as opposed to pull/pull setups. But this is personal preference and both setups work just fine. But the pull/pull could be made a little lighter. Probably not enough for night/day diff, but if you are going nuts for all out low weight, pull/pull can be made lighter.

Cheers