Below are Teacherman quotes.
“If you keep trial and erring, you will learn that "shoulder rotation" is not a part of a high level swing”
“You see....the hips rotate. The shoulders do not.”
“Shoulder rotation leads to two and only two options.
1) Bat drag....doing it slow enough so you can "stay in there"
2) Pulling off the ball....when you really "get after it" to hit the ball hard.”
I will post an overhead clip of a swing that produced over 3000 MLB hits. Although I developed this clip for another topic, it should allow you compare Teacherman’s statements to what you observe.
Rose hip and shoulder rotation