Here an overview, part of Sbeneh Outskirts Insurgency in the BF2 Editor.
The tiny blue boxes are possible ammocache locations.
The big blue boxes (sorry but is same color in Editor) are non-controlpoint related StrategicAreas. Such area's are needed to tell the BF2 ai where is an interresting area or important area on the map. In this case, the important area's are possible ammocache locations.
Non-controlpoint StrategicArea's have no capture timer and get instant captured by entering it. Those areas working like alarmzones. The bot ai notice that a enemy entered a important area (doesn't matter if a cache is spawned or not) and will recapture it. That's the way to force the bots to defend a area.
Simple explained: The bots want to recapture occupied StrategicAreas, where the humanplayers hanging around.