or you could play World at War 2005 where all these problems are solved.
A/A guns can roll up to 3 dice per combat round and may not fire more than one die at each attacking aircraft. More than one A/A gun can be used in a territory. They fire just like any other normal unit. They can also be used as Anti-tank guns and casualties.
Oh yeah, defending and attacking fighters exchange fire for one round against SBRs. Fighters accompanying an SBR have a range of 6. They also have a range of 6 if they do not participate in combat that turn. A/A guns can fire for one round during the SBR and normally in a normal attack in the same turn. SBRs can damage/destroy factories, so the stakes are higher. Factories can be repaired but if they are not, certain penalties apply. For instance, if you hit well enough, you can prevent the factory from putting out tanks, A/A guns, ships and/or aircraft. You can also bomb runways and limit the amount of defending fighters able to defend against SBRs. In short, you can actually have a real Battle of Britian. One more way World at War is superior.