Playing as Kong Rong I had a battle with Huang Shao and captured one of his generals. The general had all three options available. I was fairly intrigued so decided to employ the general. I went to find them in my court and they didn't exist and they didn't show up later.
Seems like a bug as I am guessing that you shouldn't be allowed to recruit YT characters as non-YT factions. Has anyone seen anything similar?