And it might be an oversimplification of matters, though I wonder if to some degree, the natural hunting lifestyle of the colonists/militia from rural areas led to more of a woodsy/hunting style of fighting. Less formal and organized (especially before the formalization of the army and drill tactics), and more what was familiar to the of shoot and be as adroit as possible at not getting shot. I could be totally off on it, though just one more thought to add to the mix, at least to hypothesis for rationalization around early war fighting styles.