Well, you and I have both been at the study of 'internal' for more then a few days....
I haven't heard you explain how 'internal' resists a push any differently than modern athletics would. Yet, you're sure that it is different...
When I stated in another post that Dan Harden can resist changing forces from a non-cooperative training partner without the need for conscious adjustment to those forces, there was zero metaphor in that statement. No doubt muscles are in play (Dan has repeatedly publicly cited the psoas, for example). If adjustments in his body are happening, they are virtually autonomic; and even then you can't sense or see muscles firing. But none of the athletes I know train like this, and none of the folks with athletic training backgrounds I know who've trained with Dan can relate it to anything in athletics.
Now, many others here can back this up because they've experienced it first hand as well. These are rational, and in many cases formally skeptical people.
But we can't adequately explain it to your satisfaction, so there's only one option left: go get a sampling and conduct the requisite analysis by meeting Dan or a reasonable analogue. The effort to form a western-centric model and rationale is fruitless without you working off the same data points as those with whom you're trying to engage in said effort.