My point was that if height-of-effort really mattered, then those planes would have been made as razees instead of coffins. It doesn't, and they weren't.
I've long since learned to very skeptical any new "innovation" that was actually both widely known and feasible all along. Low center-of-effort is one of those - everybody has known for centuries (literally) how to implement that. The fact that they didn't consider it worth the bother says something very important (and as I said, engineering analysis agrees - there is no significant difference in pushing effort).