Soldier's Age in the American Revolutionary Wars

Tim Ashby says:
"Rob Gaudet makes an interesting point about youthful courage in battle versus the caution of older soldiers. During the American Revolution, my fifth great-grandfather, George Ashby, joined the 8th Virginia Regiment, Continental Line, at the age of 17. During the Nov. 1777 siege of Fort Mifflin (which blocked the Royal Navy's approach to Philadelphia).

Young George volunteered to retrieve expended British cannonballs under fire when American ammunition ran low (his reward was "a tot of rum" for each projectile recovered -- from the account I have, the teenage solders treated this as a game). Grandpa George was badly wounded the next day (did too many tots of rum make him incautious?), evacuated to Valley Forge, furloughed home for the winter (probably the only reason he survived to beget 10 children), and returned to Valley Forge in the spring for training by "Baron" von Steuben.

I've often wondered if George campaigned under such harsh conditions (he was in a rifle company, and supplied his own weapon) out of a quest for adventure, or whether he was a true believer in the Revolutionary cause. His father, Henry Ashby, who had been an officer in the colonial militia, was "neutral" during the war, and I believe he was amongst the third of all Americans who remained loyal to the Crown"

RH:
This is indeed an interesting subject. At the Battle of Waterloo, were Wellington's troops younger than Napoleon's Republican Guard?