Cruisers and other naval units SHOULD NOT get the same abilities as AA guns. The reasoning for this is as follows.
A typicla WW2 European cruiser carried eight to twelve 4 inch guns, assuming that it was fairly large. US heavy and light cruisers carried eight 5"/25 or 5"/38 AA guns if prewar, twelve 5"/38 if war-buillt Cleveland or Baltimore-class ships. US AA light cruisers carried 16 early or 12 if later-built 5"/38. Japanese heavy cruisers carried typically carried eight 5"/40 AA guna, but also had very poor AA fire control systems. British AA cruisers carried eight 4" if converted WW1 ships, or eight to ten 5.25" guns if war-built. Special note should be made of the HMS Delhi, which was converted in the US to carry five 5"/38 guns in single mounts with a US fire control system, and was also viewed by the Royal Navy as an AA CRUISER. This was the same armament and fire control system carried by the US Fletcher-class destroyers!!!
Compare this to the heavy AA gun defenses of Great Britain in 1940-41. Source of the information is There Finest Hour by Winston Churchill, volume 2 of his History of WW2 series. In July of 1940, there were 1200 guns of 3 inch or larger caliber, in December of 1940 there were 1450 such guns, and in May of 1941 there were 1687 such guns, with the beginning of radar-directed fire control systems for the guns. This represents the equivalent of 100 to 140 cruisers. In addition, AA guns on land would be located either in the immediate vicinity of the expected targets or along the route to the targets that the attacking air forces must take. Ships are spread out over a much larger area, typically a thousand yards or so between vessels,which considerably reduces their ability to concentrate AA fire on specific targets.
Now, if this were a tactical-level game, with each ship representing a single vessel, and each aircraft representing perhaps 6 to 12 aircraft, I can see separate AA roles for ships, if they are the objects of the attack, or are very nearly in line to the target of the attack, like a destroyer or cruiser screening a battlehip or carrier. I have been playing TACTICAL NAVAL GAMES since 1970, and assisted in developing them. Axis and Allies is not a TACTIAL LEVEL game. It is a STRATEGIC LEVEL GAME, albeit played with miniature ships, planes, guns, tanks, and infantry, rather than cardboard counters. Giving cruisers the same ability as AA guns is definitely mixing the two levels.
