Textual: These two verses show some of the way that Mormon handles his sources. It is quite likely that his original source contained some information about the king attempting to resolve the immediate contention. However, the rest of the information here depends upon events that must have occurred after this point in time. The conversion of the people, and most particularly the understanding that some were not converted, is nothing that could be discerned by an eye witness to the moment.
Mormon has taken the basic information, and then added the longer historical perspective without attempting to mark the division between the time frames. Indeed, from Mormon’s distant time frame, there would be no significant different between the beginning of the conversion of the time when it could be said that some were and some were not converted. This is purely an issue for the nature of historical documents. Mormon is not simply recounting the history he finds in his sources, he is recasting it.