When the Lamanites arrive at Ammonihah they find that they city has been “in part rebuilt” (verse 3). This suggests that Ammonihah has not returned to its status as a major city-state, but is rather now a strategic position. Certainly there would be a local population at that place, but Moroni apparently understood the vulnerability of that particular entrance point to the land of Zarahemla. With his understanding, he not only partially rebuilt the city, but the rebuilding took the form of significant additions to the defensive capabilities of the city.
The description of the conflict at this particular location fits into the types of conflicts we see in Mesoamerica. First is the description of the defensive position as being a wall of dirt. This is a known defensive tactic for several Mesoamerican cities. Jeremy Sabloff describes the earthen fortifications around Tikal:
“Surveys of the more peripheral areas surrounding Tikal shattered the traditional persception of the Classic maya as a basically peaceful people… Ditches running along long, narrow, artificial ridges, or parapets, were found approxsimately 8 kilomters to the south of the site center and 4.5 kilometers to the north, between Tikal and the large neighboring site of Uaxactun. The ditches and parapets ran for a total length of more than 9 kilometers. The Tikal archaeologists, particularly Dennis Puleston, suggested that these works had been used to defend Tikal from attack. (Jeremy A. Sabloff. The New Archaeology and the Ancient Maya. Scientific American Library, 1990, pp. 84-5).
In addition to the authentic description of the earthen fortifications, the references to stones are arrows accurately reflects the long-range military weapons of the day (see Ross Hassig. Aztec Warfare. University of Oklahoma Press, 1988, pp. 75-80).