See Goosey's last point is important.
When a marathon runner sprints at end of race, he or she will go from aeorobic system to anaerobic.
Now logic to me would suggest that a strength athlete who takes say 4 sets of 8 to get to failure or say 4 sets of 5 with short rest, is still going to stimulate ATP or whatever on a simialr basis as 1 set of 3-4 on 90%.
Most important thing about training on say 90% is specificity to lifting event. That is why most programs of strength lifting taper down to low reps before comp.
Perhaps that is why Kazmaier also incorporated a lot of reps into his training. When you take joe's points into account, moderate weights with intensity and lots of eating also huge factors for success, assuming one has the talent.
Never be fooled by what people say they do in terms of sets, reps and percentage alone; it is the intensity that also counts and this can altered greatly by speed of movementor by rest duration as others have alluded to.
My experience is that there is a strong relationship between sub-maximal weights and maximal weights, and that there are many ways to stimulate growth necessary for great strength and power.