Agreed. I do not however do not get what you try to explain with the attached picture. Feet are still parallel? I see one in front of the other, and of the floor??? This person is pushed over easily. Can you please elaborate a bit? I would like to understand what you mean.
Assume the orientation of the feet is actually parallel and on the floor. There is only so much I can manage with my bad XFig skills in Linux.
People are vastly harder to push over in this configuration than you would think. Or otherwise my practice would go a lot
easier than it does. This structure is strong enough for me to drive in and break hooks on my arms, or drive in with my legs, and get under even while another person tries to do likewise, without losing balance in any direction. Even people with little training seem to get this pretty easy against resistance.
Pay not attention to the center axis, which we aikidoka are wont to focus on, but on the peripheral lines of the body, and how the approximate those green arcs, i.e. if you push on the hand, from either side, it goes down to the feet, not necessarily between the hands. Or pull on one hand, no problem, just extend with the other side. No harm, no foul. But this configuration is also extremely stable from the sides, so long as this configuration is not achieved by twisting the spine, hips, etc. but rather by orienting smooth bridges through the body.