I did 2 sets on each block last cycle, which was pretty high volume since I was working out 5 to 6 times a week, but I got really good results.
This time, I'm doing the standard 3x a week, but I'm going to try 1 set on 15s, 2 on the 10s, and 3 on the 5s. The only exception is that I am not adding my isolations in until the 10s, and I am starting them out at 1 set.
So during the 15s, I'm only doing compounds, and only 1 set of each. Then on the 10s, I'll bump the compounds up to 2 sets and add in the isolations but only do 1 set, during the 5's, 3 sets for compounds and 2 for isolations.
The volume will be lower than last time, and who knows... I might freak out halfway through the 10s and start doing 5 to 6 times a week again, but hopefully I won't.
I recommend you try both. Do the classic HST model first, 2 sets for each, then try the 1, 2, 3 setup on the cycle after that. Granted, it will take at least 18 weeks to know which worked better for you.