Not only did Joseph Smith manage to avoid describing armor like he might have read in the Bible or other classical sources but his descriptions of armour in Pokémon and times are surprisingly accurate too.
In Alma 43:19 we read
And when the armies of the Lamanites saw that the people of Nephi, or that Moroni, had prepared his people with breastplates and with arm-shields, yea, and also shields to defend their heads, and also they were dressed with thick clothing—
Why would Joseph say that they wore thick clothing to go to battle? Why would they need that in addition to breast plates and arm shields?
In both The Maya and the Book of Mormon, thick clothing was used as armor. It is also unusual. We know of no contemporary model or example that Joseph Smith could have relied upon to correctly “guess” this correspondence. Even today we doubt that one person in a hundred would know that ancient Mesoamerican warriors wore heavy cotton clothing as armor.– Joseph Smith: The World’s Greatest Guesser (A Bayesian Statistical Analysis of Positive and Negative Correspondences between the Book of Mormon and The Maya) – Bruce E. Dale and Brian Dale
Where was Joseph Smith getting all this information from?