Egyptian was not well understood when the Book of Mormon was published yet it appears Joseph Smith was spot on.
Evidence Central summarises:
In 1966 one critic of The Church of Jesus Christ of Latter-day Saints wrote a series of inflammatory letters to several ancient Near Eastern scholars, seemingly designed to elicit negative statements about Latter-day Saint scriptures. This man received an unexpected response from William F. Albright, a prominent biblical scholar at Johns Hopkins University. While Albright was a Protestant (and hence not a believer in the Book of Mormon), he nevertheless wrote back:
As you know, when the Book of Mormon was written, Egyptian had just begun to be deciphered and it is all the more surprising that there are two Egyptian names, Paanch and Pahor(an) which appear together in the Book of Mormon in close connection with a reference to the original language as being “Reformed Egyptian.”
Unable to offer a viable explanation for how a name such as Paanchi could end up in the Book of Mormon, Albright vaguely suggested that Joseph Smith was some kind of “religious genius.”– Book of Mormon Evidence: Paanchi, an Attested Egyptian Name
High Nibley even noted:
A striking coincidence is the predominance among both Egyptian and Nephite judge names of the prefix Pa-. In late Egyptian this is extremely common.– Hugh Nibley, Lehi in the Desert/The World of the Jaredites/There Were Jaredites (Salt Lake City and Provo, – UT: Deseret Book and FARMS, 1988), 23. See also Hugh Nibley, Approaching the Book of Mormon (Salt Lake City and Provo, UT: Deseret Book and FARMS, 1988), 282.
Where did Joseph Smith learn about Egyptian names? Would we expect Egyptian to appear if Joseph had created the Book of Mormon himself?