But perhaps you CAN use one or more UAVs to fly along WITH the fighter to supplement its missile load with missiles that can be launched from the UAV but guided by the fighter's electronics
That may be a possibility in the future, but I don't think the technology is available today to make it happen in the Air to Air mission. UAVs are pretty good for surface attack missions because the scenarios are less dynamic. There are still a lot of visual cues from the cockpit that are needed in the air to air mission.
Some of the problems that have to be looked at are visually identifying targets. A passenger jet coming out of Iranian airspace looks a lot like a bomber on a radar. The Rules of Engagement require a visual ID on the target before you launch missiles. That turns the fight into BFM/ACM requiring a lot of communications, teamwork, and instant decision making. A UAV doesn't provide the Situational Awareness required to be effective.