Mormon does not describe these contentions, but the union of two people with different languages and cultures, whatever their common roots, could not have been easy. No difficulties are mentioned in the reign of King Mosiah1, either because the new arrangement was still in its “honeymoon” period or simply because they were not reported.
However, Mormon’s source material surely included more details, so we can safely assume that Mormon applied a heavy editorial hand, preserving the fact without discussing the specifics. It is quite probable that these contentions were discussed more fully in the lost 116 pages. Mosiah 1:1 begins with the statement that “and now there was no more contention in all the land of Zarahemla, among all the people who belonged to king Benjamin.” That statement is irrelevant unless it refers to significant contentions that came before. Mormon’s brief statement here stands in place of what would have been a more complete accounting (given Mormon’s editorial habits).