I need some rule clarification.
Here's the scenario,
The Professor (a Survivor - my character) tried to enter a building and failed. It spawned two survivor NPCS (Jimmy and Sailor). After the "talk to talk" they decided to go their merry way with no bartering.
On a later turn I tried again enter the building and spawn a generic militia NPC. Now Both NPCs ( the Jimmy/Sailor group and the militia guy) are in sight of each others. Does it trigger a talk to talk between them? Do they start shooting at each other in a testosterone frenzy? How does that work?
I usually remove NPCs from the board once I've dealt with them as a player. However...
By the rules they will test for Friend or Foe (16.2). This could lead to shooting.
If not go to Talk the Talk. If both sides score the same number of successes, they leave each other alone. Any other result means they will shoot it out.
As an option, you can designate the side with the least characters as a Player. This could allow them to Barter.
Hope this helps.