Nephi made two sets of plates—the “large” plates and the “small” plates. Although the plates plates were made for the more spiritual things, he nonetheless makes a complex political argument on them. Given that Nephi felt he was called to rule the people by revelation, and that the challenge to his rule from his brothers was serious enough for him to lead his people away, it is no surprise that he would feel a need to defend his right to rule through his personal narrative.