Jarom produces his evidence that they were a prosperous people. They had accumulated many valuable items, and their wealth is also evident in "fine workmanship of wood, in buildings…" Archaeology rarely finds much of the "fine workmanship of wood" due to the poor preservation conditions in Mesoamerica, but it is certain that any wealthy center in Mesoamerica displayed that wealth in their public architecture, precisely as Jarom indicates.
It is interesting in passing that this particular catalog of weapons of war includes those most common in Mesoamerica, and does not mentions swords, scimitars, or bows. Since those items do show up later in the Book of Mormon, we cannot presume that they were not present here, but simply that for some reason Jarom did not think them important in the catalog of weapons of war. It is possible, as a speculation, that Jarom's listing of the wealth of the people is precisely a catalog of items of value to other Mesoamericans, and therefore the more typical armaments are mentioned as evidence of their acculturation, even in terms of warfare.