Nice setup clean n neat.
However.
If surface moves 60 degrees and servo moves 120 degrees -- the servo power delivered to surface is doubles and slop shown at surface from servo gears is halved .
That's basic eng

If you have all the power you want with 1-1 then go for it -It's your plane and your hobby -
It does however, double required work of the servo.

Also IF you consider the "linkage" being a small pulley (or gear) driving a twice as large pulley( gear) attached to the surface-- then you get an entirely linear setup - with no changing angles- the same as direct hookup but with double the power at the movable surface