you can manipulate the knee whereas if you are rotating your "back" hip just prior to FFS then you will have to roll over the knee....which in my mind if done correctly makes the back knee action a result of hip activation, and a "non-teach".
Lord knows I'm no expert, but here's what I think...
You can try to turn your knee, but that makes things worse/slower.
You can use your back hip to turn the knee, but that's too slow. And the hip doesn't fully turn in time anyway.
You extend (or triple extend, or whatever others call it) your back leg, which turns the knee, which turns the heel, which turns the hip.
OK. We're really not far off at all. I see the 3x action as a lot more kinetically connected in sequence than some others and I do agree with you that this is what is happening, even if I might put the sequencing slightly different. I just feel that it at least feels more like throwing the hip and pulling the knee rather than the other way around. However, now we're getting into details so small and so insignificant in how we teach it that it's nitpicking at this point.