Why the Kii class fell short of a balanced fast battleship

What do you think of the Kii-class design?

Drachinifel likes the overall design but considers its protection insufficient to fulfil both battleship and battlecruiser roles. It makes more sense as an improved battlecruiser serving beside a more heavily protected battleship.

Japan hoped Kii could fulfil both halves of the repeatedly revised Eight-Eight programme as a fast battleship built in substantial numbers. Its design sits closer to an up-armoured battlecruiser than to a battleship given additional speed. Against G3, Kii has one more 16-inch gun but less speed and protection, while the British ship can bring its guns to bear over wider arcs. G3's armour has a reasonable chance against 16-inch fire at medium to moderately long ranges, whereas Kii needs longer ranges for comparable protection. An Amagi successor paired with a more heavily protected Tosa successor would make a more convincing division of roles. The reservation concerns asking Kii to replace both types.