Teheuti
I think the key is "should". Essentially what you are saying is: If a numbering system "x" obviously fits a set of cards "y," then x should be considered to equal y. That is, "If it is possible, then it must be true."You see, that's what puzzles me: internal evidence (TdM's actual structure) is hard evidence; and frankly, when a numbering system has as straightforward an application to trumps as the medieval Irish bardic numbering of letters does, the obvious fit, it seems to me, should itself be so considered, but here it is not. Which is okay of course, but this does inherently limit what the 'historical' threads here can ever resolve (since documentary evidence of early tarot is almost nonexistent). But believe me, I do appreciate care being taken to avoid science drifting into mysticism (I only wish cosmologists and quark theorists took such care, for both have drifted irretrievably into mysticism, that is, away from empiricism, just as psychiatry has abandoned the empirical science of psychotherapy for the mystical swamp of prescription drugs).
Historically speaking it's more appropriate to consider: "There's a potential for x to have been equated with y. Now let's see if there is any evidence that someone actually did equate the two and when. And, if not, then does the evidence discovered suggest any other possibilities?" Science and history are continually revising what is known based on new evidence (even if it may take a while to get the new paradigm into everyone's head).
You might want to start a new thread on the medieval Irish bardic Tarot. I have no idea what that is and would like to know, but this thread is not the place to discuss it.