The words "Spaghetti Western" come to mind, but then the word "Brusesploitation" and "Hong Kong Action Cinema" the latter of which really should and probably does have a better name.
But then...those movies are all kind of fun. As in cool, hip, action packed, gory, violent, sadistic, nihilistic, and all the best possible things that off-Hollywood has to offer.
Buffalo Boys kind of comes short in the fun department. Here and there you see a little gem of a moment, but that is it.
The plot never gets into the Western depth and the action is never really as fun as what you would expect from a Hong Kong action flick.
In other words, it never goes over the top enough with the action to really make an impact and it never really goes full nihilistic new wave western enough to hit that cord either.
It tries to play it safe and the wow moments it delivers are things that we have seen before in both genres without the fun of being a genre trope.