I can think of this as the only way to stop such ahistorical behavior as B17s just sitting otr, their human gunners having no intention other than to fire their weapons at aircraft above.
When you do decide on a production (non-beta) field capture method, make sure that ground vehicles are needed to insure field capture. Let paratroopers continue to do damage, but have them take out fuel or ammo, etc. Allow only tanks to take out a key central building, like a command bunker.
Also, in beta, it might be an idea to implement an AA vehicle for fields, in hopes that players will use these instead of B-17s, since they would make smaller targets.
Finally, only allow use of gunners while bombers are off the ground during production (as you implemented for the WB engine).
Once field capture becomes a ground issue, instead of an airborne one, I believe ackstarring will end to a great degree, since .50mgs don't do a whole lot to an AFV, but a 75-88mm cannon will put any grounded aircraft out of its misery PDQ.
As for now, this is a beta, so I don't expect any changes tomorrow, but please make note of the type of response it arouses here, as well as in other online Flight Sims.
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129 IAP