i think smaller ships, like.. the fletcher and such need more small machine guns on the decks.. something like the 20mm Oerlikon thats on the new PT-boat model the FH team made. crew members used them to shoot down planes, i believe..
Dont forget 4 Inch Pom Poms and .50 cal AA Guns.
4 inch Pom Pom? Don't you think it should be 4cm? :) The Battleships will have some less AA, to keep the poly count lower. (Nothing serious, mainly the 2cm single mounts on Tirpitz and Prinz Eugen) The destroyers have some more heat, at least some of them.
That's good to know, watch out those Pilots who make themselves big by eliminating the Fletcher you'll have a nasty surprise in the future.