Ammon notes that when they began their mission, they had hopes of converting a few. Perhaps after the difficult times mentioned in the preceding verses, a few might have been optimistic. Nevertheless, they were able to convert large numbers, far beyond what they had expected.
The most important statement is found in verse 33, that these converted Lamanites, now known as the Anti-Nephi-Lehies, showed greater love for God than even the Nephites. This is an important theme for Mormon, as he is writing at a time when he knows his Nephites will be destroyed. He knows that it will be future Lamanites who will read what he writes. He wants those future Lamanites to see themselves similarly to the Anti-Nephi-Lehies, who were able to turn to repentance after a long history of traditional teachings, and not only accept the Nephite teaching of the gospel, but do so in such a way that they could be seen as more righteous than the Nephites.