I've had this happen a couple of times now. I find a stack consisting of a hero with two Champions as escorts. The recruiting price is high (600+ Gildar), rather than the usual 200 gildar range. The hero joins my faction, the two Champions go neutral. The game dialogue does indicate that I should be hiring all of them.
I'm posting this in a separate thread for clarity purposes. People are getting in the habit of posting individual bugs, or responding to the threads that show the problem they've seen.