Hello craig,
I am not an arma member but since I mostly study ringeck, I though I would have a bash. Here is my take one that.
True edge false edge:
The only time I have seen it define in original text is in meyer, and basically it seems that it is really function of the position of the fingers on the hilt.
See
http://schielhau.org/Meyer.p5.html
Of course Meyer is relatively late compared to Dobringer, ringeck and the usual suspects so his understanding may be different from the one before
For the Sheilhaw
It really depend whose original text you follow, but I think what matter is the position you end up in. So you should really end up in a position similar to the one on meyer
http://schielhau.org/Meyer.p11.html , of course the altitude of you hands will depend where his strike was intended to land.
The idea is to be in mechanically strong position so that his strike is deflected and we hit him (shoulder or head according to the original sources. This is achieved because your hands are kind of supported by your body, the angle body handle is very strong as far as collapsing towards you. The same concept is used in the zwerch as well
So, bearing in mind the true edge/false edge we really have to option either you turn the sword or you turn the front hand.
If you turn the front hand well this is technically a short edge according to meyer definition, but this is what used to be the long edge before your front hand started to move.
So I would say it does not really matter if you turn the sword or not as long as you end up in the right position at the end.
I hope I did not confuse you too much.
Philippe
One Ringeck to bring them all In the Land of Windsor where phlip phlop live.