Where did they borrow or copy it from?
Everywhere and nowhere. Why assume that Asia is the Sun Source of All Martial Arts? We have been fighting the way humans fight for a couple million years. The answers are still pretty much the same.
There are fads and trends in combatives as there are in everything. I got a copy of (I think it was Dakin Burdick's) thesis on the evolution of military combatives in the US Army. At some times boxing was emphasized. At other times it was wrestling. In any case you see the same sorts of moves in ancient Asian scrolls, old European Manuals of Defense and Egyptian Papyrii.
The human body hasn't changed much. The ways of taking it apart haven't, either. The WWI film has material that's relevant to crawling around in trenches because those were the conditions. Bayonet fighting with a big, heavy bolt gun and a long, sturdy bayonet is a little different than doing it with an M-16 and the current standard issue glorified butterknife. Those are little things.
To quote the late great RAH close combatives have always been about "Do it first. Do it fastest. Do it nastiest."