All my bikes have the washers in the clutch .
The 65 Leader clutch is quite heavy even with a well lubricated cable, it's not helped by the shorter operating lever on the Leader handlebars. On a long run it does make the hand tired.
On the Arrow the clutch is lighter and I thought this was a result of the slightly longer handle bar lever and less tight curves in the cable.
The MK2 Leader has an even lighter clutch, the only difference is the adjuster is near the handlebar clutch lever and not at the other end. Every bike I've tried has quite a heavy clutch apart from Allan Mayo's bike which has the adjuster in the same place. When I re-looked at the Arrow's set-up this also has non standard levers with the adjusters near the handle bars.
I think it is possible to have the adjuster in a mid position on the cable, so it's on a straight run rather than on a curve bit of cable and get the same results.
( I have come across bikes with stiff clutches due to the push rod being dry or slightly bent )