Well... was going to type some more, but it would be for the most part redundant with Kent. So, what Kent said up above.
And I was just looking at one small aspect -- the mechanics of cutting.
I'd also emphasize that while each group out there does things "differently", they are still (generally) internally consistent. You don't take one aspect from one and attach it to some other aspect from another. All sorts of interesting variations occur but in the end there is (usually) an internally consistent and coherent basis for most of what each group does. So they will disagree (sometimes quite strongly) about how things should be done. That is normal and natural given the differences. But usually they have a fairly solid foundation of basics like how to hold the weapon correctly.