Reps per W.O. as per Waterbury Article

In Chad Waterbury’s article he mentions how greatly the reps can vary in different W.O.'s if the sets remain the same.
For ex. I do 9 sets per bodypart, however on light days this is about 180 reps and on heavy days this is only 90 reps.
Before this article I was not fully aware of this discrepency, however now that I know, I am wondering what is the correct rep range for any workout, heavy or light?

NASA,
Ah, the 10 million dollar question! How many reps during a heavy or light workout? Well, unfortunately I can’t give you an exact answer unless you were in Tucson and I could assess you myself. But, I don’t want to leave you empty-handed so I will give some gross generalizations.
First of all, it is a myth that heavy and light workouts should consist of completely opposite rep schemes. This is only necessary if you are working to absolute failure (which I hope you are not). Therefore, with some trainees, I might have them perform 60 total reps on light/speed day, whereas they might perform 70 total reps on heavy days. It all depends on where their weaknesses are. Confused yet?
But as a general rule, perform half as many total reps for 85+% of 1RM training as you do for light 50-60% of 1RM training. This should get you started on the right track.

Mr Waterbury,
Thank You very much for the information. I would also like to tell you how much I appreciated your 100 reps for recovery article. My chest had always been my weak point, however after 14 weeks of doing 5 to 8 sets of 30 pushups on my non-chest days I now have a chest that looks like it belongs on someone larger (and stronger.) Thanks again.