If I saw the North Korean army marching down the street in my town, I would run, not out of fear of the invading forces, but to get out of the way of the steel rain that is about to come down....
Only a complete fool or a suicidal lunatic would take shots at a large group of well armed men trained in military tactics marching in formation or even just moving over ground. Superior firepower is an overwhelming force when it is concentrated, unless the opposing force has better weapons - which is why I would move before the Made in the U.S.A. steel rain arrives....
I remember how we dropped daisy cutters on the "elite" Iraqi Republican Guard in Desert Storm - wiped them all out en masse. Monitored radio traffic picked up their cries for their mothers.