"Some of the difference that is different - or so I think - is that when you swing, you swing your primary lever with your shoulder. You use dead hands and after transition the shoulder turn and CF keep your hands where your shoulder turn gives you max leverage.
When you hit, you still swing with you shoulders, but you also swing your primary lever around your left shoulder. You delegate some of the swingers' pivot work to the right arm. But you need a proper pivot action as a basis to be sucessful with the TGM hitting."
Gets even more complicated when you consider that you can pull with the left side or the right side.