The second link is interesting, not the advertisement for a book of techniques but the comment about the coaches teaching a limited amount of techniques. Sort of like what we saw in early Judo history and even in Gatka i.e take a few techniques and drill them well.
I suppose you'd find the same historically, the difference between a random soldier and a fully professional well trained swordsman with decades in the salle.
Also, dear op, don't wear it on your back. :s It looks weird and is impractical. Unless you're a ninja. In which case sure whatever.
I'm not suprised at the lack of historical evidence supporting this, scabbards can be hassle enough as it is which is probably why we have lots of art showing either naked blades or scabbards in manu. Although still, it is suprising how fast one can draw and cut so I wonder how big a hindrance it really was? I mean what if you had to scale a wall or some other such task?
No language is justly studied merely as an aid to other purposes. It will in fact better serve other purposes, philological or historical, when it is studied for love, for itself"
Mind now changed...