2 as the Pearl version is just one day, the other is the one that did all the damage. Throw in the West Virginia with the twin 16 inch turrets too. She scored on her first shot at a Japanese BB. Talk about payback
What one class of BB would you pare it all down to? Bear in mind, the Nagato had 16" guns. The ships won't be identical (USN, IJN, RN, etc.).
Should we try to balance the firepower of the main batteries somewhat, though? Individual gun range and power, number of guns, guns to bear side fore and aft, armor?