eliot feldman
I went ahead anyway and just finished one with that kind of construction, and I'll tell you why: I was in Sicily years ago at some Greek temple ruins. The guide explained that most of the temples were completely destroyed by earthquakes over the years but that some managed to survive to some extent (like the ruins we were standing in). And the explanation for that was that the ones that survived a bit were constructed with thin layers of lead between the stones. Apparently that kind of construction provided for some sort of shock absorption. So why not try it for a mallet handle?