also, on this same lever thing, and owning an old KZ, with a cable clutch, I'll note that the "actuator" on that bike does this exact thing....
The cable end terminates on a sort of "disk", about 2" in diameter, and when the cable is pulled, the disk rotates; the disk is attached to a "helical" (i.e. thread type, here again, a "thread" is just an adaptation of an "inclined plane", wrapped around a central axis) and when the disk rotates, the thread causes a change in direction along "IT's" axis, turning rotation force, into linear force, pushing on the rod to press the spring loaded clutch disc.
soooo.. the larger the actual "pully" diameter you have, given friction free movement, the less effort needs to be applied to the lever (that imaginary line from the center of the pully, to it's outer diameter), and less pull distance as a result, with a greater outcome of "work performed" by the "effort".