Blue Monkey
Archon Without Portfolio
Your approach is certainly valid for loose agents. Those are barbarians. We're talking a little at cross-purposes - I'm looking for a way for minor characters associated with particular civilizations (such as Flashman for the British, or Vidocq for the French) to appear without necessitating another unit design.I have seen 4 or 5 different unit types emerge from huts and different names for tribes. The agents "creeping about" could be a result of random "investigation". Further you could use a set per era.