another question i will repeat is do you think gmt could have taught (lets use yang 64 as the example) differently to the various masters/teachers/students that he has taught one on one or in a class setting.
Move for move, yes. Master Sin has never been a big stickler for "this hand must go right here " everytime as opposed to Master Hiang who was. And there will always be some variation when someone learns and does a form. Personally, I think spending a lot of time on it is missing the forest for the trees.
But having said that, I can see a lot of differences in the forms from when they were first taught (yes, I was there for most of them) and drilled and drilled and drilled and some of the versions today. I think what happened is a dilution effect. Some popped up to the Sports Center, learned something once, took notes (this was in the days of 200lb camcorders mind you) then never took the time to soilidify the foundation of what the particular form had to offer.
So it comes as no suprise that when some of us see obvious additions, subtractions and just plain wrong stuff being done, we do stop and just shake our heads at it.
"Pain heals, chicks dig scars..Glory lasts forever"......