seeing how only 49% of the battles were won by the larger forces from 1950-1999
wouldn't you also venture to say that what made those tactics successful was the small units having automatic weapons such as ar15's ak47's instead of back in the day when one man fired one round?
No, not at all. Let me explain: FA (Full Auto) weapons have been prevalent on the battlefield since ~WWI (although yes, FA first appeared in medium machine guns it quickly moved to PDW's (though that particular term had yet to evolve) and later light and medium MG's.
Yes, there was a huge change when MG's entered the scene in WWI (arguably the most significant change in warfare within the last 150 years) but that doesn't begin to explain asymmetric fights whatsoever. South African SF ('Recce' they called them) and later Merc's quickly found out. especially because of their medium calibers (.308, in this case) weren't exactly conducive to individual effective FA fire (I have many other examples, if need be). Semi-auto reigned supreme due to it's controllability and effectiveness. 'One man, one round' is
not the pivotal point in the change in warfighting; individual prowess and flexibility most decidedly, is.
The advent of micro (and, to a lesser extent, macro) maneuver warfare is what really changed things. By all accounts, if the current US military, even avoid of current technology, were to somehow travel back in time to 1968 in Vietnam, I have no doubt that they would have decisively won that conflict.
So, a correlation of the availability of FA small arms and conflict domination is invalid and a large oversimplification, IMO.