Interesting, thinking along those lines and in this sense the American lack for formal training, and hence the only training they had, might have proved to be temporary, albeit unplanned for, advantage.
Also to consider, the kentucky long rifles (with rifling in the barrels) were considered to be slightly more accurate at longer distances than say the British Brown Bess smoothbore – another slight tactical advantage. However, the colonies did not have a standardized model long arm and most were blacksmith made, so supplies of all weapons were limited, something that could be overcome with the well-equipped and suplied British army.