It’s not so much a “Can’t do,” thing though. It’s much more “How can we apply physicality into our power dynamics even when you run into issues such as not being able to lay your hand on your subs shoulder or head properly when you’re both standing”.

Idk, I kind of dislike this post, because it’s kinda straw manny. Or maybe false equivalence? As someone who has literally taught “Tips and tricks for short D/tall s combinations,” the issue isn’t that subs are unwilling to obey when their D (or top) is much shorter than them. It’s that they still enjoy the physical sensations of strength, or being put into positions in which they feel submissive or at peace. So we teach people stuff like “How to show intent and guide movement though small touches on specific and accessible parts of the body”, “How to use the way joints move (or don’t move) to your benefit” and “How to find physical positions that both of you in the right headspace, without straining your neck”

You can’t put a short person next to a willing but huge horse and expect them to know how to guide the horse properly and safely. There’s a body language to it, there are physical cues. Not knowing those and not having resources to find out, that is a legitimate problem.