The arm drag is not exemplary of applied IS, I guess most of the time anyway. But a good arm drag may as well be... iriminage? One side allows them to go their merry way, the other goes your way, in that case launched from... a parallel stance. If they resist the pull, well, more solidity for you to pull/drive yourself forward. If they don't resist, well, they just get... dragged. Fun side-effect of good external movement, one side drives the other, the other side drives the one. Did you push off them, or they push off you? Oh, looky that, you now have their back, what fun you two shall now have! Callooh! Callay! If you are invested in the outcome of who is the satellite, and who moved in absolute positioning in space, rather than in the relative positioning of the bodies, that belies a certain fixation on outcomes that is not becoming of slaying Jabberwocks.
Ok I had to read that about five times, but I think I understand... I understand that the body mechanics involved are relative, but we strive to moves a little as possible. Energy conserving, more efficient and faster. But this is no golden rule. In many techniques (e.g. irimi nage ura, in fact most ura waza) we obviously do move, but only after balance has already been taken.
BTW Never heard of Jabberwocks, now I did (look it up) and sure do not want to run into one
Thanks your input helped.
Glad I understand at least the basic level. I suppose more advanced level is about correct dosage.
Some shihan display a kind of impulse like technique and in that exact moment take the balance and execute a technique. I suspect this eventually everything you can see 'at the outside'.