Re: Baseline skillset
Vectors not mathematics. Got it.
As for the "if you knew or your instructor knew," you are moving merrily between the particular and the universal, and leaving undefined references in your wake.
I was not offering an opinion, only offering some admittedly-secondhand-but-from-credtable-sources information which appears to contradict, at least in part, what you said. If you believe that information is incorrect, I'd love to hear about it. I haven't studied with Ushiro sensei, so all I can profer is what I have. In any event, that tidbit has no relation to what I or my instructor might or might not know in other contexts.