Timothy Walters Kleinert
The topic of whether the internal stuff is "natural" or unnatural", "regular" or "different" has been covered in the past... I'm pretty sure more than once. (It is "natural"/"regular" in so far as that everyone has the capacity for it, but "unnatural"/"different" in that it is a learned skill that is d@mn-hard to figure out without someone showing you how.)
Standing erect is a learned skill -- so is walking. Most of us figured those out without a great deal of directed training, just passive observation, trial and error. If -- and I'll just continue with hypothetical mode -- if the learning model you are suggesting is true, then the mere fact that it is a learned skill is not that informative.
A better learned skill model for comparison along the lines of what you are thinking may be swimming. There are, in fact, large proportions of people who do not swim at all, do so only haltingly, or with what amounts to a life-threatening lack of efficiency. And there are others, like me, for whom swimming is as "natural" as the learned skill of walking. Not that different in pattern of distribution in the population from the possession of martial physical efficiency.
Swimming, like martial art, is a critical survival skill. If it is not internalized and made intuitive it cannot be reliably effective in survival situations. I have had to teach adults who never learned to swim, how to swim, not merely for enjoyment, but in highly compromised survival situations. It was my introduction to the critical observation of bio-mechanics in what, to the people I was relating it to, often seemed counter-intuitive.
It was and remains important for people to learn from what they already know. The more you emphasize the differences in what is being taught from what they know, the more you divorce their new learning from the existing intuitive foundation that is necessary to make it function effectively. In teaching swimming, mere trial and error does not work -- or at least, not past one serious error that, at best, will destroy the trust of water needed to swim well. Nor did it work trying to directly "reconstruct" their mechanics based solely on an experienced impression of well-developed swimming motions. That typically confused existing "natural" actions and resulted, literally, in floundering.
It required, not merely a baseline understanding of fundamental "not drowning" to accomplish - but a "feel" for water, its nature and the ways in which the body CAN move in it. Negative reactivity of any kind impeded the development of the necessary "feel" of actual water and movement in it. In transitioning to the more efficient true swimming, it was vitally important to show the connections between what their bodies already knew to do and had done, and what their bodies needed to learn to do in the same intuitive manner -- if in a somewhat altered way. I find much of value in that experience. I have applied a great deal of what I learned to my aikido training and observing martial movements.
In short, for body skills on this order -- if you accept that efficient swimming and aiki
are of the same order of developable body skill -- (apart from natural prodigies) there is no short circuit in the development of such skills apart from recapitulating the essential rudiments from which they are derived, and then following from those steadily along a slightly different but organically related evolution.