Another third of the colonists didn't care who won, reckoned John Adams. With only one-third of the colonists supporting it, the revolution was lucky to get off the ground at all. Bringing in an army of outside consultants won't guarantee success. The British made the redcoat army their largest overseas military expedition ever by beefing it up with Hessian mercenaries. The Hessians were defeated and captured hundreds at a time in the first years of the war, when they should have made the biggest difference - including 900 caught the morning after George Washington crossed the Delaware.
Training is always worth the price.
After a year of watching his amateur army get beaten up all through 1777, Washington spent the winter at Valley Forge. Politics can snatch defeat from the jaws of victory. And you thought finessing your office politics was tough. Gates didn't realize it, but he was being played for a sap by the Federalists in Congress. Alexander Hamilton first egged on Gates and then tipped off his old boss, Washington, who had to block the plot with soft words because treating it like the mutiny it was would have ripped the army apart.