My point was that you made statements that appeared to assert specific claims. Saying we can’t know is more realistic.Stances in CMA exist because of observation and the inherent affordances of a position; if you want to do x, you must do y. The resulting position was codified and trained.
When you look at stances in terms of affordances rather than fully thought out positions that someone created uses around a lot of things make more sense.
I expect much of early martial arts was like this. We can never know of course, but we can speculate and make links.
Ultimately it doesn't matter. We now have chambering and it can have multiple uses. We can choose to do it or not.