It really doesn't matter all that much, as the functional part of the linkage is always one direction, that is, your foot puts pressure on all the linkage, down to the clutch, and it "pushes" back, thus pretty much negating the slack.
Of course there is a limit--cracked Z bar / fork, or severely worn bushings, etc
Frankly, if I were going to try and "improve" clutch linkage in this day and age, I'd look into hydraulic. The type used on my Ranger, example, with the a throwout type actuator, is incredibly simple with little to go wrong