I'd like to see them g00b.
 In my personal experience, I've noticed that picking off ack with wing-armed machine guns are especially difficult, due to the convergence ranges - it kicks off a lot of dust all around the machine gun, but not many rounds seem to hit it. 
 On the contrary, with centerline armament it seems a lot easier to take them down, even with 'weak' MGs such as 7.7mms armed in early 109s or HMGs like the 50cals on P-38.