Mark (Abrams) - I don't know if I fully answered your question. I had only a few minutes and wrote my reply quickly. In particular, this aspect:
I heard from a number of sources, that if you were a Japanese student, depending upon which instructor you aligned yourself with, your "ukemi experience" could be predictable, based upon the pecking order of the major instructors and who you taking ukemi from
I don't quite understand what you mean here. Could you go into a little more detail and I'll see if I can address it.