If delayed as an armament sailor until lvl 120, they would need full experts and 180 vets to reach the reload cap, and would have a little over 1,000,000 repair TA.
Through all this time spent delayed, you would not have access to any of IJN most powerful AA guns, like the 2x 4.7" A, you would have to make do with something like the lvl 22 2x3.9" D which have very short range.