It is quite certain that Mormon has historical records of more Lamanites joining with the people of Anti-Nephi-Lehi. The reason given, that they “saw that they could not overpower the Nephites” may justify a return to their lands, but not a conversion. We don’t know why there were Lamanites who continued to come to the Anti-Nephi-Lehies. They could have been some who were previously converted but not gathered into a single body that made the journey. They could have been some who were considering the message of the Nephite missionaries, and accepted it later than the others. Since they also bury their weapons, we may presume that they were converted to the gospel, and not simply desiring a new place to live.