the bismark can fire salvos, the yamato can't. the bismark's cyclic rate per gun wasn't so much better than the iowa's so why are some people giving the bismark a higher firepower rating than both iowa and yamato with just eight 15-inch guns?

because the bismark can fire more salvos within a given period. cyclic rate is only half the story. to fire a second shot, you have to see the report from the first. and the bismark's guns with a flatter trajectory, could produce the 150-foot fountain sooner than the iowa's, especially at close range. so it has several seconds advantage in adjusting elevation and loading for the next round.

the iowa and the yamato (assuming the latter can salvo) can heave more shell on the first salvo. but the bismark can fire the second salvo sooner and with more accuracy.