formula-damage(guess)

Maybe because it's I played normal, but laser reduction on enemies wasn't a big problem.

But if you watch carefully, as jerryfanfan noticed, pilots don't fly with their gun triggers depressed constantly. They shoot in bursts, and the lull between those bursts hurts high RoF/low dmg guns. Also, manually aiming for your pilots is a dramatic improvement.

Try it: enable pause when selected target is destroyed. Then select a pilot and use the camera to follow behind him. Aim targets for him. As soon as one is destroyed, click on a nearby target which is roughly travelling in the same direction - not necessarily the nearest target. This way it's possible to take out an entire wing of fighters in a continuous salvo. When it pauses at the final kill you'll see all the explosions paused which makes it look like you shot them all at once like Killer did.

Left to itself the AI tends to fly away and wheel around before selecting another target to fire at. That's why manual aiming is better, common sense will tell you it's easier to hit a target which is travelling away from you because you have time to tail it and line up your shot. The AI is probably simply picking the nearest target, and since the nearest target also tends to be one flying towards you, the AI has no time to shoot and has to wheel around to line up an attack run.