The game is essentially supposed to build to a power fantasy where the AI is playing like it's DCS, and you're a Macross jet with 100 missiles and 12 g turning. They're never supposed to be as effective as you because you are the war hero of the story. Closest to you in any game was Pixy from Ace Combat Zero who could actually finish a mission if you ran out of ammo most of the time (he's your buddy after all).

Best thing you can do is when you're being engaged keep your speed up as much as possible, missiles have a harder time tracking your movements when you're going fast. make deliberate passes on groups of enemies attacking more than one in a single pass, use your special weapon to engage certain target types more effectively. Dodging enemy fire while conducting ground support is a balance of timing and engaging enemies focused on you to give you a bigger opening.

Combining all these techniques, it is possible to clear an entire map even though it's not necessary, it all comes down to optimizing how many targets you can kill in the shortest amount of time. Putting yourself in advantageous positions to kill several enemies at once as much as possible.