i agree. at some point one of my armies was wandering around, my aim being to "train" the leading family member and to get some xp for the troops...i got to a 10 stars general and 3silver chevrons or better for the troops in around 20 turns...basically each autocalced battle at least 3 or 4 units would gain one chevron. But battles I fought myself, most of the time one unit would gain any experience at all (or none...).
Although most battles, of course, were neither heroic victories nor crushing defeats. They were simply regular clear victories...and yeah, _lots_ of enemies were killed and/or routed...