The ships were not intended as independent fast units but as standard line battleships able to fight beside 13.5-inch-gun dreadnoughts. Saving machinery weight and hull length made it practical to order them in numbers without sacrificing their main battery or battle-line protection. Their arrival would push 12-inch-gun ships into reserve while retaining those older hulls as a second layer that could be reactivated in wartime. That depth let the Navy cover secondary theaters, amphibious fire support, and battle losses more quickly than new construction could supply replacements.
Chapter · 26:42-29:22
A line battleship built for fleet depth
Lower speed made the R class affordable in numbers and compatible with the older battle line it was designed to reinforce.