I just finished a MM multiplayer battle where I had taken one wako raider and a few loan sword ashigarus among others. I was really surprised when the battle loaded to see that one of my loan swords had turned to a wako raider. So I had two of them, which is impossible as they're kind of a hero unit. How the hell did this happen?
PS: Just for the record, I played another battle with the very same army composition and nothing happened fortunately.