Merrick, I think you are misunderstanding point being made in this video. He is not saying that these different names are what Joseph is doing, but what the Nephites did. When the Nephites saw an animal that reminded them of a similar one from the Old World, they would name it based on their experience. So when Joseph was translating, he translated into English the name the Nephites wrote, which may have been for an animal that was only similar to the animal with the same name in the Old World.

Remember that these are only possible explanations. The Book of Mormon does not claim to be a textbook on the domestic animals of the cultures of Ancient America. These details are not essential for us to understand for the Book of Mormon to accomplish its objective of testifying of Christ. So we need not get hung up on such trivia. The critics are straining at gnats while swallowing camels.

It is also important to understand that God nor Joseph Smith have revealed just how the Book of Mormon was translated. Such details can only be guessed at by scholars from the hints in the limited historical accounts. Therefore, knowing the mechanics of just how this occurred is not something the Lord felt we needed to know. It does provide an interesting historical mystery to be solved by scholars, which is just fine.