Had an odd bug in a recent game.  Ongr the Unbound was lingering around one of my towns as I tried to build up forces sufficient to deal with him.  I saved and reloaded a bunch in here, mostly on other battles and to control which champion I got at 100 fame.  Ongr attacked the town a few times in there but, not in any of the saves I kept.  Eventually I felt ready to give him a try and I put my sovereign in the town anticipating an attack.  Sure enough ... however my sovereign was nowhere to be seen in the battle.  Instead he appeared outside the ruined city after the fighting was over.  So I reloaded.  Ongr attacked again.  I chose auto-resolve.  Same result.  Sovereign outside the ruined town.  So I looked at the units stationed there and I found a spearman unit that somehow had 18 spearmen in the unit.