The Lamanites’ leader in this war was Zerahemnah. We do not know his origins, but his name hints that he was probably a Mulekite, a descendent of Zarahemla. Thus, he may have been chosen as a leader because of his knowledge of the land. At least as far as his honor goes, Zerahemnah seems to have been a good leader; he refused to take the oath to Captain Moroni because he knew of an oath’s importance. The Lamanites and Zoramites may not have valued an oath that much, but the Mulekites had been more integrated into the Nephite worldview. They had sworn a covenant under King Benjamin, and knew the importance of solemn oaths, which the Zoramites had repudiated.
Book of Mormon Central, “Why Would Zerahemnah Not Swear an Oath to Moroni? (Alma 44:8),” KnoWhy 152 (July 27, 2016).