There is more than that even, check out 6-M-1 The Downstroke Sequence. Feet, Knees, Hips, Shoulders......................each component Lagging and Dragging.
Lag in all its forms. Like Hogan said its a "chain reaction" or did he say "chain action"? You can see them on video for sure, but feeling them is what its all about for the player especially at the #3 pp in the first joint of the right forefinger and/or knuckle. If there is a hierarchy of Lag that is the King Lag. After thats gone, if you havent hit the ball yet, only bad things happen. Your hands are in Homers words "chasing the club". I can feel that. How a 15 handicap, retired guy figured it all out Ill never understand.