Do you have links to the slow mo vids by chance?A lot of amateur golfers ( and some pros ) Fight this all the time. Very similar to the pool stroke. If they don't have a slight transition pause at the top of the backswing , they will 'swing from the top' . This causes loss of power and the swing gets out of the grove and miss hits the ball. Very ugly in golf.
In pool , you must start the forward swing at the same speed you took it back and then accelerate THRU the OB.
Its hard to see live , but recorded in slow motion makes it really easy to see the flaw.
Good luck all ( me too ) lol