First of all, whether or not scholars were aware of it at the time makes no difference, since (as you say yourself) Joseph Smith had "no resource materials". Now, if Joseph Smith
did have resource materials--materials which noted the historical use of stone and clay tablets, and papyrus, but not metal plates--and yet he still chose to claim that he translated from metal plates, that would be more intriguing. Yet, since he did not have access to these materials, it is not surprising that he claimed to translate from a medium for which there was no historical evidence at the time.
Secondly, consider the likelihood of someone with a third-grade education and no resource materials using his imagination.
Long before they had any knowledge of the Komodo Dragon, Europeans described and wrote about giant reptiles. Long before the advent of tank warfare, H.G. Wells wrote of battlefields full of steel beasts. Neither the Europeans nor Wells required knowledge from the Divine to do so.
Really? So if Joseph Smith had described writing on clay tablets, or stone tablets, or papyrus, that would be evidence
against the authenticity of the Book of Mormon? I'm convinced that had Joseph Smith described writing on any of these mediums, Mormons would consider that evidence of the "authenticity" of the translations.