DaVinci probably has received a significant amount of credit for some some simple drawings that may have been rehashed from previous historical war machines. I have no proof in these matters but early civilizations don't receive near the credit they deserve for their technological development either.
I just think DaVinci's designs, drawings and sketches need to be taken with a grain of salt, that's all.
An aside here: I have read in several places he wrote from right to left. I believe he was left-handed. No biggy. I just thought it was interesting. Can anyone confirm?
Thank you.