When joseph smith translated the Book of Mormon, he translated into his own langage and he used terms he was familiar with. he used words like steel to describe some sort of mixed metal even though steel hadn't yet been invented then. and he used a then common expression that fulfilled his translation needs.
If he had translated the book using terms that the nephites used or everything tutanka this or chakara that. we would be lost and so is is god's design that we understand his book JS used common language.
