How Japan accounted for Nelson and Rodney

Were the Yamato-class ships designed against Nelson and Rodney, or did Japan ignore the threat they posed?

Japan did not ignore them, but relied on its speed advantage to dictate when and how it would fight them.

Nelson and Rodney's guns and protection still made them serious opponents, so Japanese planners did not simply omit them from threat calculations. Their low speed, however, allowed faster forces to choose the tactical circumstances rather than accept an unfavorable action. That advantage could determine whether the ships were concentrated against the Nelsons, bypassed, or engaged only on favorable terms. The exchange illustrates how speed can shape an enemy's plans even when it does not change a ship's striking power.