If every Japanese capital ship became a Number 13

What if all Japanese capital ships in the Second World War had the Number 13 design?

The 18-inch guns and common 30-knot speed would make Japanese surface operations much stronger and the fighting bloodier, although the answer still expects the United States to win.

The scenario replaces every commissioned Japanese battleship and battlecruiser in December 1941 with a fully worked-up Number 13. Eight 18-inch guns and a 30-knot speed are the main advantages identified. Battles historically fought by the Kongo class would become much more dangerous for the opposing force. A fleet sharing that speed would also have more options for supporting operations. The assessment still expects an American victory, but at a greater cost in surface fighting.