Test with AI v AI so you can actually see what they are doing. Even against cargo planes the AI isn't a one shot kill every time, but it doesn't take it long at all to send it down in flames.
I think there is a case for less accuracy on the Average Setting.
Nate
It seems there is a difference in behaviour. The Excellent skill level fires closer to the target than the Average Skill level, and is less wasteful.
That said, it is still pretty accurate on Average.
Nate
AFAIK, the Drop Tanks are not included in the 1-100% in the mission editor, that is just for the internal tanks. As far as I understand it, anything above 68% starts filling the rear tank.
Nate