not the massive horse-using cultures that Smith describes in 14 different places in the BofM
The opposite is true. Horses are rarely mentioned and never in the context of riding or pulling wagons.
"And they said unto him: Behold, he is feeding thy horses. Now the king had commanded his servants, previous to the time of the watering of their flocks, that they should prepare his horses and chariots, and conduct him forth to the land of Nephi; for there had been a great feast appointed at the land of Nephi, by the father of Lamoni, who was king over all the land." (Alma 18:9)
The horses were owned by the king, and used as pack animals. His father, Lamoni, also owned horses and used them as pack animals, as part of the royal entourage.
"Now when Lamoni had heard this he caused that his servants should make ready his horses and his chariots." (Alma 20:6)
These chariots were not the horse-drawn conveyances of Ben-hur fame, but regal litters, well appointed, and carried by men. Kings in Mesoamerica were not expected to walk, and roads were not well suited for the wheel.
"And they also had horses, ... which were useful unto man..." (Ether 9:19)
This verse refers to the Jaredites, (2000 bc?) and doesn't tell us how common horses were, or what they were used for.
"Whose arrows shall be sharp, and all their bows bent, and their horses’ hoofs shall be counted like flint, and their wheels like a whirlwind, their roaring like a lion." (2 Nephi 15:28)
This is just a quote from Isaiah.
"Their land also is full of silver and gold, neither is there any end of their treasures; their land is also full of horses, neither is there any end of their chariots." (2 Nephi 12:7)
This was another quote from Isaiah.
"Yea, wo be unto the Gentiles except they repent; for it shall come to pass in that day, saith the Father, that I will cut off thy horses out of the midst of thee, and I will destroy thy chariots;" (3 Nephi 21:14)
This is a prophecy which refers to our day.
"And now it came to pass that the people of the Nephites did all return to their own lands in the twenty and sixth year, every man, with his family, his flocks and his herds, his horses and his cattle, and all things whatsoever did belong unto them." (3 Nephi 6:1)
This was about 26 AD, and all it tells us is that some men owned horses.
"And it came to pass that the people of Nephi did till the land, and raise all manner of grain, and of fruit, and flocks of herds, and flocks of all manner of cattle of every kind, and goats, and wild goats, and also many horses." (Enos 1:21)
The after thought of "also many horses" seems to indicate the opposite; that horses were rare in comparison to the other animals. (Circa 400 BC)
There is nothing here that indicates that horses were anything but rare, luxuries of kings, and never used in war. Fully a third of the Book of Mormon is devoted to the subject of war, yet there is not one verse that mentions horses having any significant role in warfare.
Prof. Lundelius responded to my inquiries and provided a horse bone from Pratt Cave which dated to BC 6020 – 5890.
This bone wasn't found in Mesoamerica, but it wasn't far north of Mexico, either. Need I point out that it was found in an area far more conducive to the preservation of bones? It also cuts the previously supposed date of horse extinction in North America almost in half. One bone is all it takes to rewrite scientific theory. We are dealing with a lack of knowledge; there are too few samples to draw meaningful conclusions.
You haven't proven Joseph Smith to be a liar; you merely prefer to think of him that way. Guilty until proven innocent.