So, who cares? My nomenclature does not have to equal yur nomenclature, but it might be jhelpful if we could translate back and forth.
Indeed. To OP, if you don't like the word "metaphor", then say "model", or "viewpoint", or whatever you want. Physics are definitely (obviously) present in aikido...but that's not all there is to it. Nor is it necessary to view aikido as a physics problem in order to get it. Eventually, on some level, your comprehension has to encompass that, but you don't have to come to an "understanding" of what's going on in terms of vectors and forces and whatnot.