I was not suggesting either scenario was practical ( 1/4 " or 2 " ). Either results in the surface realizing an equal sum of TORQUE with a given servo at 1:1 ratio. How it is achieved is the variable. Model specific requirements dictate the minimum control arm overall length.

Either scenario has equal leverage and resolution at a 1:1 ratio. Mechanical advantage is not a factor, its non-existent until such time the control arm exceeds the 1:1 relationship. The servos TORQUE/FORCE is again not a factor at a 1:1 relationship, its all the same.

3D planes do NOT require a 1:1 relationship, this is FACT. A 1:1 ratio will net equal travel arcs of the servo and control surface. Simply put there is NO absolute in this regard. Some models and surfaces may perform better with less surface deflection than others suggesting a skewed ratio is preferred if not desired while implementing mechanical advantage. These things are model and pilot specific. It all boils down to the desired degrees of surface deflection, most servos are limited to a 60 degree travel arc in one direction, a 1:1 ratio will net 60 degrees travel. For example, 60 degrees aileron throw on my 40% Extra 3D bird is NOT required. It works best with 35-40 degrees deflection.