Ok, I'll see if there is any door frame or area in my apt or maybe outside, where I can do some door frame drills and film it for you. I'm almost 100% sure I can't do it right, even though I understand it, haha. I definitely don't feel like my shoulder is being pulled taut ever in my back swing.
Also, just watched this amazing video from the same guy, Ben from Tread Athletics, and emailed him about drills and tips on how to throw faster if your ER or IR dominant. So I'll post on here if/when he replies. Fingers crossed.
The video talks about how you can start to see great velocity gains by doing these "Daddy Hack" drills, haha. It's a similar idea as the Hershyser drill, I think. Striding long and not getting onto your plant foot until real late. Letting the momentum and that coiling of the upper body happen, all WHILE your lower body is building speed and momentum down the mound to then unleash your upper body.
Really cool stuff and I'm going to try working on these ideas. I think with the bat in my hands or hand and then so on, it will really help me to FEEL this idea of striding forward, but while keeping my upper body back and centered over my pelvis, feeling he weight more in my glutes than my quads. Which he says then allows you to still have all that energy saved to release when you finally land. Not sure I totally understand it 100% yet, but it's the same as your videos. Their like time bombs, haha. You get it more or less first watch, then understand more and more and more little parts each time there after, haha.
https://www.youtube.com/watch?v=eGLzbEMe4qo