Thanks, that does make sense. Although to me it doesn't sound like being 'unthrowable' per se, so much as being un-unbalanceable. Which I can certainly see the utility of.
No matter how stable I am if someone strong enough bends their knees, wraps their arms around me, and unbends their knees, they can lift me. (and therefore throw me if they want)
That's why I said "stability training (in a sense)" - stability alone doesn't really cover it, although that gives you the general idea.