American's want short sound (or reading) bites. Instant information is what is required, correct or incorrect. It really does not matter much. So things like " squats for legs and benches for chest" or "8-12 reps are best for everyone" always all are easier to digest and understand mentally. Thinking & understanding training styles, for the individual BB'er, requires planned thought process. Too much mental energy for some who come here. And besides, their lips have to move a lot when reading that long stuff.
If anyone wants better involvement of the trap when when doing HI-pulls/cleans than use the example of the Olympic lifters. Thick and muscular traps/upper backs as the goal. Contract/squeeze the traps during the lift, keep them in mind as a muscle group. Do this during the middle and top range of the Hi-pulls/clean mostly, using the arms as a starter for the lift. BB'ers will depend too much on the arms for pulling all the way up and not enough on the traps themselves. Making the Hi-pull/cleans more affective for the traps, SS shrugs right after your pulls.
I started serious rack shrugs my first year of college football. My senior year using 900+ for partial reps (3X3's usually) and with-in the 750 range for full reps. I was, by no means, the only lineman to do this. I was just one of a few. I weighted between 270-280 as a senior (I weight 235-240 now at 6'2 and 35 years old). We would also stand in the full DL position and hold an extra heavy weight for 20 to 30 seconds (straps of course...from a PR). Also did this when in the full top holding contracted position of shrugs (trying to touch the ears in theory). Both outstanding movements. Some did Hise shrugs, which added a lot of muscle to a lot of guy's I have trained with back than. A very overlooked body power exercise. Good Luck.