If the USS Iowa went toe-to-toe with the Yamato, who would have the advantage and why?
This is the front turret face of the Yamato class battleship. The armor is 26″ thick:

You will notice a nice, even, 16″ hole in it.
Here is the back side:

So, Yamato’s thickest armor cannot defend against the 16″ 2700# armor piecing shell fired by the North Carolina, South Dakota, and Iowa battleship classes. Yamato’s belt armor = 16″ and deck armor = 8–9″
This is the dispersion table of USS Iowa. Target is 200 x 200 yards:

At 25,000 yards, due to the curvature of the Earth, Iowa would be hull-down on the horizon to Yamato. At 36,000 yards, Yamato wouldn’t even see Iowa’s gun flashes.