American Continental Regulars, after being properly trained, could stand toe to toe with some of the finest troops in the world. Witness the battle of Monmouth where Continentals slugged it out with Guards battalions.

Someone beat Burgoyne at Saratoga and it wasn’t militia. Continental Light Infantry carried Stony Point at night with the bayonet only, muskets sans flints. Later the same Light Infantry stormed a redoubt at Yorktown.

Irregular warfare did not win the War for Independence. A professional army of regulars got the job done. With the able assistance of the French Navy and to a lesser extent and rather lately, the French Army.

Regarding irregular warfare in Empires, my concern is the AI. It has been all the AI can do to wage semi-competent conventional warfare in the TW series thus far. Unless some very clever programming has been done an extra wrinkle could widen the gap between a decent player and his AI opponent.