Building a boat-hull Boeotian

[hoplite14gr]

Actually I made a back joke about the "no literrary evidence" trying to make fun of "the no evidence crowd".
In fact I agree with you mostly, espacially for the Beotian! From bronze age to 670 B.C. shields were light.
And Chigi vase will support your point on round shields.

Full metal faced shileds survived but a large numberof the contemporary ones had only metal perimeter and metalic emblem like Acropolis and Olympia museum examples so you might have a very strong point on rawhide - stronger than you think.

I believe that the culprit for making the round shields heavy (like the Vatikan example-somewhere I read oak not willow) was king Pheidon.
The idea is that the "heavier" packed formation will prevail over "lighter" packed formations. And I believe it did

Homer describes shields that he saw in temples but they were probably not used in his time.
Dan Howard wrote a paper on Homeric shileds and he probably is more correct tha any one when he says that the center was reinforced and most penetrations took place at the perimeter.

To summarize I agree with you 100% for the Beotian but not completely on the round shield.

Kind regards