Isn't it possible to create named characters for the slave faction and give them an 'immobile' trait, ala EB?...otherwise half the cities you encounter in this game have the garrison gone and a peasant unit on guard. What's the challenge in that?
I have them leave forts on me but generally they seem to stay put in cities. You just need to make a trait with a large negative movement bonus and assign it to all generals of the slave faction to immobilize them. The trouble with doing it that way is that a lot of rebel generals will be generated in the field and you likely don't want them locked into place. You could, of course, manually give this trait to those generals that begin the game in cities via the descr_strat file.
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