Try setting different waypoint objectives like Attack Fighters for instance. Set several waypoints in the same area instead of just one.
I do not think you can set random skills within the same flight but you can load different flights with different skills randomly with a script similar to this one
http://forum.1cpublishing.eu/showpos...&postcount=117 .
What do you mean by "rolling a trusty old D20 over and over again" ?