Yup, DMG, p. 85 says so, with: "*Treat peasants/levies as up to 1-1, men-at-arms as 1-1 to 1, and all levels as the n+1 hit dice category." But I've always taken that to mean that, say, a 4th-level fighter NPC should be treated as the "4+1 hit dice" category for xp purposes. If that is true, it...