Have you looked at opening up your chest, lateral seam, under your pec, around the scap to feed slack to your shoulder and improve shoulder positioning?
If you know anyone with HawkGrips I’d highly recommend having them hit those areas. I’ve seen great improvements with athletes should position using HawkGrips paired with a Marc Pro.
right arm internally rotatated want thumb pointing out.
Lock out your elbow
Left thumb out
Elbows flaired out
Closer to the body
I recommend going to the floor first.
Rebuild the skill pattern. Carl Paoli has some great progressions that will show you where the restrictions are.
Freestyle Movestrong 1 on the Cody app is great.
Yes external rotation is one that needs attention.
Limitations with internal rotation need to be addressed too.