If one kills Ofnir and Grabacr with time left to spare in the last mission of 5, your wingmen will say exactly why they fought and how they enjoyed being your wingmen. Better than it sounds by far.
In Ace Combat 04, the same song always plays while selecting your plane and weapons in the hanger bay... except on the final mission of the game. The music is changed and you can hear a voice over the intercom talking about how even though the ISAF nations are of different nations, they all fought and died together and will finally win the war together.
In Ace Combat 6, during one mission, on the verge of court martial, you and your disgraced wingman destroy a WMD stockpile and are ambushed by over fifty enemy fighters, with no hope of survival. And then every single allied squadronshows up to help you.