Keep in mind that offline all the fighters in the drone circle are flying about 225-250mph so other than angles under 30 degrees off, essentially shooting from the drone's 6. You will be learning snap shooting for an average speed 50-100mph slower than combat in the MA. Even 6 shooting at differences in elevation will be effected by this.
Hitech has never mentioned if he did this right out of the AAF fighter gunnery manuals for WW2 AAF state side training. But, those are the speeds training took place at and the optical gunsights used a 70Mil ring instead of the 100Mil the pilots would use in combat. The final chapter of the 1944 AAF manual for gunnery school states that once deployed to combat the pilot will have to be brought up to speed on the differences of combat speed and how to use the 100Mil ring to compensate.
Over the years I've watched a lot of players shoot late.