The problem is that there are a lot of variables at play, and any one, or combination of them, could be causing the issue:
Master cylinder push-rod adjustment (adjusts initial push point)
Master cylinder span adjuster (allows more fluid to push)
Slave cylinder piston size (defines how much fluid flows with lever travel)
Clutch stack height (defines biting point, resistance, etc)
Clutch pressure plate (defines spring height/preload)
Springs (defines preload, resistance, etc)
Spring caps (defines preload, spring height, etc)
then you have things like wear and tear - clutch friction material, basket tangs, inner hub wear, springs going out of spec, air/water in fluid, etc!
Changing a few of these at once can sometimes make a small problem in each into one big problem, so you're better off reversing as many changes as possible and adding bits one at a time.
For the clutch slave, later ones (recessed star pattern) will work fine with early bikes anyway.