@Narvik:
OK back to topic. Dug in infantry or artillery dont get a preemptive shot at charging infantry that run up the beach or cross the minefield, so why would AA guns fire preemptive at attacking aircrafts ? Its pretty much the same.
Also, the previously mentioned parallel with the surprise attack ability of submarines doesn’t really work. Submarines are designed to be stealthy – their defining characteristic is their ability to hide from surface observation by diving underwater – so it makes sense for them to have the ability in the game (as they did in WWII) to sneak up on a target unobserved and put a torpedo into its side before anyone realizes that there’s a sub lurking nearby. Anti-aircraft guns have no such stealth abilities. They can, to some extent, be camouflaged from daytime observation by the application of netting, but that doesn’t give them the same kind of stealth abilities as subs, for several reasons. First, visual camouflage of this type confers no advantages at night (since neither the guns nor the camouflage can be seen). Second, an attacking air force will know perfectly well that the juicy targets (such as cities) will have batteries of AAA guns clustered in and/or near them, even if their exact location isn’t known. Third, WWII subs and AAA guns operated in a fundamentally different ways. Subs operated in essence as single units (though they could sometimes operate in groups) whose purpose was to fire large and expensive weapons (torpedoes) singly or in small numbers at a target which was carefully tracked and aimed at with as much precision as possible. WWII AAA guns, to have any chance of hitting aircraft overhead, had to operate in large numbers and had to function more or less like firehoses, pumping hundreds or even thousands of rounds into the air in the general direction of their targets. And sometimes they didn’t even actually aim at specific targets; rather, they would fire “box barrages” designed to fill a predetermined volume of airspace with an optimal pattern of sharpnel designed to create the maximum chances that an aircraft flying through that airspace would be hit.
Even more fundamentally, however, the concept of a first-shot advantage for AAA isn’t really meaningful. A WWII battle between AAA on the ground and bombers overhead isn’t like a duel between Wild West gunslingers in which the advantage goes to the first man who gets his gun out of his holster. Bombers don’t drop their bombs until they are over their target, whereas AAA guns will usually open fire as soon as the enemy planes are in range – so in that sense the AAA always gets “the first shot”, but that doesn’t translate into any kind of guarantee that the AAA will get the bombers before the bombers bomb their targets. The effectiveness of WWII AAA ground defenses didn’t hinge on who got the first shot, it hinged on things like how many AAA guns were clustered around the target and how skillfully they were used.