It is a pretty good video......gives some good thoughts on how the lower half can dictate the top half
I myself wouldn't be trying to actively drive anything.....I believe it is more the pressure down the right leg that helps keep things in sequence. I would prefer to feel things in my feet instead of thinking knee
If you push down the right leg around transition (or feel the force down)...then the left knee and hip systematically counter balance by going left....balance naturally ...as it's our instinct to counter balance and not fall on our face. Then the driving happens later...so the left knee and hip can get where he mentions (into a stopping point as far as lateral) without having to drive anything....If you drive there then it gives the motion a sense of not been able to drive again,,,,so things will stop near impact with the lower range of things and the top half is want to take over.
I think many people can still get in trouble by actually driving anything in the swing, (knees,arms, hands), especially the poorer golfer who has not much control of things or can save himself by making little alterations along the way...... it's opposite forces of working one way (feeling the force of one direction) that really enables many parts of the swing to move in the other direction....force against force, holds things in place.
And driving the knee is all relevant to how much torso rotation you have in place....if you have minimal rotation and lift the arms and then drive the knee then things will not work out as planned and like wise if you have lots of torso rotation
I think what he says would work great for someone who has a decent amount of turn and keeps his hands reasonably short on the backswing....
A good video however as he explains something that should happen
Here is a few pics of me at Pebble hitting a driver from 18th tee (2002 I think)....poor quality and not a time in my life when I was swinging my best...but gives a decent enough look of the down happening, before the forward of the right knee occurs.... we should be feeling behind if we want to drive forward...