And on the second one, I remember a quote saying the difference between life and death is one 'sun' (as in shaku, sun, etc. the Japanese sword measurement system). Is that the same one? I never read it as referencing "arrival time" but as length/reach/distancing, but I suppose now that I think about it, it is quite open to interpretation as to what he meant exactly...
Well hell-arrival time, distance, timing, all end in one sword getting there fist eh?
The Jubei idea-who the hell knows if it really happened was so clearly difintive as a model in that they each appeared to arrive at the head shot at the same time. the witnesses could not see it. Only Jubei knew the truth.
Live blades proved the margin was just a blade width.
As for one shot / one kill Id save that for a sniper. Anything else is not so clear.
Here's a thought I've trained with seal and Spec ops who demonstrated some room sweep models that exhibited principles I was taught in a 600 yr old Koryu. That is to NOT count on one hit, but cut and move, cut and move.
In the room sweep model it was one tap next target, one tap go back and tap and so on. It increased you chances of shocking one while making the next one defensive and your moving made him lose target acquisition (meaning killing you) and when you tapped at him you went back at the other guy while moving..if you had the chance to move.
The obverse was you would go in an unload on one guy…only to discover the guys buddy was unloading on you from across the room. Make sense?
Ancient battlefield knowledge- that probably had to be re-learned or re-discovered as hard lessons to Israeli commandos then taught to American soldiers.