How extra anti-aircraft cruisers could change destroyer armament

How would twenty-nine additional D-class and C-class anti-aircraft cruisers affect the Royal Navy?

They would add substantial air-defence firepower, especially for Mediterranean operations and Norway, and could reduce the pressure for uniform anti-aircraft destroyer armaments.

The hypothetical addition of twenty-nine D-class and C-class anti-aircraft cruisers would give the Royal Navy much more gunfire protection for its task groups. Mediterranean operations and Norway are singled out as places where that firepower would help. More specialist cruisers could also change the pressure to build destroyers with a uniform anti-aircraft armament. One alternative suggested is a mixed fit with twin 4.7-inch mountings forward and a twin 4-inch mounting aft.