Here’s something else to take into account.
Thickest armor on USS Iowa - 19.5 inches on the turret faces - 17” armor plate over 2.5” of STS steel.
Armor penetration capability of Russian Kornet-D semi-man-portable antitank missile: 51 inches - and that’s after penetrating explosive reactive armor.
Modern antishipping missiles are even larger, thereby having even more armor penetration capability.
The advent of the missile propelled shaped charge spelled the end of the battleship as it renders armor beyond a level sufficient to protect against small arms up to 5” gunfire irrelevant.
A modern battleship need not be a copy of a WW2 era battleship anymore than a modern fighter is a copy of a WW2 era fighter.
I’m looking at the role these ships can play in a modern fleet, not their entire design.