I have been testing blue side Hawk batteries in the desert map and have noticed that the location seems to have something to do with whether the missile launchers, radar and supporting AAA guns will show up in a mission. I believe that a large, static site like a SAM battery must be located near a logistics node such as a city or some of the vehicles may not appear in a mission. Further, the computer seems to prioritize inert, static objects such as the ICC, then the radars, then the AAA guns and finally the launchers if the entire system is not present during the mission.
My Hawk batteries consist of two separate locations in the Desert_targets.ini file and consist of three launchers, one ICWAR, one HIPIR, one ICC and one supporting AAA gun of the computer's choice. The radius of each location is 200 meters, the centers are 100 meters from each other and the batteries are arranged in two half circles that complement each other.