Instead of thinking about a horse’s primary thought determining the bend, consider the idea that the primary thought should direct the movement. Where a horse is thinking is where it should be moving.
I have recently been in discussion with somebody who asked me how to marry the concept of using the outside rein when neck reining a horse with my opposition to using the outside rein in two-handed riding.
People who are preoccupied with the hindquarters stepping sideways as the important component of a hindquarter disengagement are missing the point of the exercise. All the important stuff happens at the front end before the feet even move.