Why rate of fire can outweigh shell size

Did rate of fire matter more than shell size in some naval battles?

Yes; the Royal Navy often favored triple 6-inch turrets because their rate of fire could deliver more explosive on target than 8-inch guns.

The useful measure is the total explosive that actually reaches the enemy. A larger shell delivers more per hit, but a weapon that fires much more slowly may put less destructive weight on target over the same period. Faster-firing triple 6-inch turrets could therefore produce a larger useful volume of fire than 8-inch weapons in some cruiser actions. That tradeoff helps explain British interwar preference for 6-inch cruiser batteries despite the appeal of greater nominal caliber.