I think that having starting garrisons in the Minor settlements (PSFs) in regions that belong to the Eleutheroi would be a good idea, if the AI would keep the armies in the garrison than factions would have to fight at different spots to take full control of the province. Take the capital but not the PFS and the Eleutheroi garrisons would have devastation lowering the income of that region. Look at Sardinia, when the Sardinian unit (or units) get made, than there can be groups of Eleutheroi occupying the inland PFS, instead of the total control that Carthage has at the beginning as of now.

Would the AI armies stay in the PSFs?