Re: The most troubling question
The organisation where I train differentiate between yonkyo and sumiotoshi, also. Yonkyo seems to be more of an 'outside' technique, whereas sumiotoshi is done more from the inside (that makes sense in my head). But that might just be a quirk of our style, I don't know. I've also never seen anyone in our dojo demonstrate or even speak of jujinage, even though I've always considered it one of the 'main' techniques that everyone seems to practice.