"Fuel Porking" is a valid tactic. Irritating, yes, but valid.
Balancing reality vs. game play is a very tricky situation. You can't have as much reality as some would like and still make the game playable.
Whether it is the usual lone "Pony" that drops his 50 megaton bomb from 15K and destroys the VH without so much as a scratch, or the 50+ P-38 raid that destroys everything on the field including the field mascots water dish and every blade of grass and fly away unscathed, field flak is dismal at best at times. I notice in AHII that field ack is much tougher to destroy, but is it as lethal as it could be?
There is no clear-cut answer to all the questions. Beef up the field ack? Beef up the fuel stats? Harden the fuel bunkers? The hardened Ack will make it more difficult in some respects, but the volume of fire at a field under attack seems wimpy.
Every field that I have seen pictures of had many more guns and ack emplacements than what AH fields have. Maybe part of the answer lies in not so much increasing the accuracy, but increasing the volume of fire. Put some .50 caliber mounts around the field and on some buildings. Also put in a few more large AAA guns. That might slow down the divebombing Lancasters and the ground strafing B-17s a bit.
Will this help? I don't know. But a single aircraft should not be able to destroy a field’s fuel, ammo or VH and fly off untouched. Realism vs. playability. Again, a tough mix.
LTARsqrl