Booze,
Y'know I could have sworn my original post did this already....
Scenario 1:
An F4U-1C and F4U-1A both put a half-second burst into the inner half of a target's left wing--say, a P-47--under full convergence range. Using my settings, that's at 200yds. The 1C will likely take almost any opponent's wing right off at that range. Depending the target, however, the 1A may not have caused enough damage to finish off the airfoil. Under the current model, the enemy escapes and continues to fight without problems and possibly gets a shot of its own at the Corsair before it can be finished off.
Now, let's change the damage model so that the amount of damage caused directly correlates to the amount of lift lost:
The 1A puts in his half-second burst and fails to destroy the wing, however the hit was sufficient to do 60% damage to the airfoil. The target has suddenly lost 60% of the lift produced by that part of the wing, leading to a stall of the left wing. The pilot is unable to recover, perhaps because the aircraft was already at a high angle of attack while maneuvering against the 1A, and the stalled wings snaps the aircraft into an unrecoverable spin.
Scenario 2, with Wing Spar damage added:
The 1C and 1A both put their half-second bursts into the wing, striking the main spar. The 1C's cannon destroy the spar and the wing shears off. The 1A, meanwhile, not only shreds part of the wing's surface (damage to the wing spar shouldn't take the place of damage inflicted to the airfoil itself) but seriously damages the main spar, perhaps within 60% destroyed. Although the P-47 is flyable, he can no longer press the fight as the damaged spar wouldn't be able to withstand the G-loading of hard maneuvering and threatens to snap under the stress. Compounding the situation is the shredded airfoil reducing the amount of lift the wing can generate, causing the aircraft to roll to one side. While the P-47 may still be flyable, in all probability he's out of the fight (perhaps the creak that plays under high G-loads can occur at increasingly lower airspeeds and G-loads as an audible queue of damage to the spar?)
This is why I say the effectiveness of cannon have to some degrees been exaggerated by AH's damage model. I'm not arguing that cannon wouldn't inflict more damage, my argument is that the all-or-nothing, your wing is either there or it isn't damage modeling makes machine gun fire less effective than it SHOULD be. Cannon would remain more potent, but machine guns gain an additional benefit by not needing to destroy a component entirely to have an effect.
Nemisis,
The problem there is what is the rate of increase? An equal, tit-for-tat correlation between the amount of damage inflicted and amount of lift/effectiveness lost is cleaner, easier to understand, and less arbitrary.