I "was" not only sliding and rotating my hips but also turning them on a sweeping plane. very close to what may be called a hip plane.
this down and around I do not find in any competent swing I have looked at.
The best swings show a very level hip turn.
I got out a couple of my shop adjustable roller stands. One stand just under my butt. As i go to top my right cheek kind of sits on the roller, I slide along roller only 2-3 inches then as i rotate left I feel my left cheek sit on the roller and if I am swinging my butt kind of rolls around end of roller and If I am hitting it kind of stays on roller.
This is far from automatic yet and the feel is very different but I have looked and looked in a mirror and I think I am on the right track.
I use a second roller in front of right thigh an I try not to bump it .