The Incas performed brain surgery. Based on the percentage of healed trepenations their survival rate was as good as modern surgery in the 1980's...
And what does that have to do with comparing Iowas and Yamatos? That the Incas actually took the time to learn something about the brain andperferm surgery is a cultural and scientific marvel but it would not have been a war-winning weapon.
I'm impressed by Inca brain surgery, but the Incas never put a battleship to sea, did they?
The Yamato was built to to slug it out with other battleships and bring heavier and superior gunfire to bear. It did nothing of the sort and the Japanese never found another use for it, except as a kamikaze. It was a tremendous waste of resources, manpower and money. The Japanese themselves realized this and tried to convert the third ship of the class into an aircraft carrier, but couldn't do it because they lacked the resources.
For all the fear the Yamato put into people's hearts, it was the survivors of Pearl Harbor, 20 year old battleships, that managed to sweep the seas of the Japanese surface fleet at Surigao Strait.