The underlying fact address the realities HERE in North America, and not details of the political alliances ( or lack of) in the British Isles.
England could not afford to field and equip a standing army in the colonies. Instead, the crown used the strategy of establishing armories near every population-center in the colonies. They required every able-bodied male to assemble and train and drill with their supplied muskets, balls, and powder periodically. Whenever England wanted to mount an assault against a foreign enemy in North America (generally French and their Indian allies), they would press masses of colonists into service to launch those assaults. The colonists had to abandon their farms, businesses, etc, to satisfy their service to the king.
Thanks to that model (a self-sustaining remote army made of obedient colonists), when the colonists decided to kick the traces, England found itself in a really hard spot. They had to put a lot of regular-army forces into the fight and supplement them with German mercenaries, and still they lost. There are lessons here.