Well...(sounding like a broken record) We have an Elbow Kata... Six basic movements with the Elbow a beginner must master to improve in rank. I know it's not along the lines of IMA...but all our techniques (Weapons and Empty Hand) focus allot on the "elbow" and "feeling it" during the execution of any movement. It seems to make a big difference.
Well sure. Basic Japanese models-(meaning lacking real information) if trained well will help to a degree to get the focus off the shoulder. However, the real information is part of a deeper process from internal to external that blows the lid off of conventional budo movement to the point that those same Japanese shihan couldn't touch someone who knows this well. You'd walk right through them.
It's only magnified with weapons, but I have never seen the completeness of the skill in any Japanese teachers movement. I think the Japanese Nage/uke model has severely hampered real progress.