:facepalm:
The system is already implemented.. "Fallout Behavior" is what it's called...in the oblivion cs, it has nothing to do with bethesda's game "Fallout 3." As long as the current AI package on two NPCs do not have "Skip Fallout Behavior" (fallout, meaning a secondary effect) flagged, when they are near, they will talk to each other "How are you?" "Been better" "Oh, any news from the other parts of tamriel?" "Nothing I'd like to talk about."
HeyYou was just trying to be helpful. It's not his fault that you are using a term that many people (even modders) may not necessarily understand, especially with the limited amount of explanation you provided.
That being said, it is likely possible, though difficult and would probably require OBSE.