Umm...yeah...jumping into this thread 37 pages later so there's no wayt i'm going back to read them all. If I'm repeating previous ideas, I didn't read it the first time, so I'm not really repeating it from my POV.
First off, the best way I can see to handle this would be to make everyone join a tribunal first, and then get promoted to the 'elite' forces of the cabals. Players would keep their tribunal abilities and have the cabal's abilities added once they're promoted. For the MC, add something like a commander skill, or foray, or something that means they get to take their troops out of the country, since there are already Imperial troops wandering in a lot of places they 'shouldn't be'.
My only question would be would the Harlequins then be able to join THREE groups? Since they have no tribunal, it would seem to make sense that they could be recruited by a foreign tribunal and then be promotoed to the local cabal to avoid blowing their cover as a spy or what have you. Would make the Harlequins insanely overpowered though, so if that's the way to go, then some Harlie powers would end up leaving, which I don't like the idea of. Option two would be to make the thieves guild a 'tribunal' since that's the closest thing to law Teron has. Instead of controlling the obvious guard NPCs, they would get to control any NPC rogues/bards across the realms with leadership.
Option three - New Teron tribunal:
Council of guilds
Leadership - PCs may command NPCs of the class of the corresponding guild - mercenaries guild members would be able to control mercenaries and barbarians, thieves guild would get to control rogues and bards, Torrum members would get to control two out of Sorcerors(good), warlocks(neutral) and necromancers(evil) based on their alignment (good control good and neutral, evil controls evil and neutral, neutral characters control warlocks and have only 50% success rate with sorcs and necros). Or something like that...The CoG would have 3 leaders - one from each guild.
Probably going to curse option three by saying this but I thought I'd mention that I got the idea while looking at a map of Calimport from the Forgotten Realms DnD setting. The whole city is broken down by guild boundaries, etc. with a great many more guilds and since Teron is kinda like that.......
Stopping here so I don't start rambling more than I have - go ahead and cheer