Hi Dave,
I think you'll get the most bang for the buck from working on your release, but that can mean doing shorter and slower swings, which not every golfer loves doing.
In the driver swing recording, you'll see the shoulders pull around the body through impact. That gives the look at the end of the video of the chicken wing and the hangback. It's apparent in the iron too, but a little less so. Either way, I would always start with some form of 9 to 3 with the goal of getting to some version of hit hard stop short. If you have a hard time stopping short in the finish, then it's a classic sign that you are hitting it too much with your shoulders and arms and not enough with your hips, legs, and core.
Perhaps you can post a video of a 9 to 3? Do you still hang back in shorter swings?
Tyler