Give companies an option to become Insurgents if they have no claims/territories yet.
A company that has no claim 7 days after its creation unlocks a choice to become "Insurgents": Syndicate-Insurgents, Covenant-Insurgents, Marauder-Insurgents.
These sub-factions will still get their respective faction bonuses but will ultimately belong in one class/category, these players no matter what sub-faction they belong to can choose to work together and declare war on any towns they choose including their own base faction. However, they can only declare war on a faction that has a total claim of 4 or more territories (this is to help avoid companies from abusing a faction unfairly).
Their quests will still be taken on their respective faction NPC’s and influence gained will be added to a new white bar at the top of each town’s icon indicating how close the territory is from rebellion/revolution. Eliminating insurgents on PvP mode is the only way to defend from their influence but influenced gained for completing quests as insurgents are halved.
Occupying a territory as a sub-faction will automatically disable the company’s insurgent status and revert back to its normal status after 48 hours. PvP influenced gained would also be disabled into the newly occupied territory for 24 hours, this is not only to allow them to prepare and flourish but also decide among themselves about their new plans, especially if they worked with other sub-factions who supported and joined them or if they want to keep pushing their momentum forward and continue more rebellions on other towns with nothing to lose but only gain.
Last mechanic that will ensure not one faction will dominate the majority of the map (6+ claims) or demoralise a losing faction for too long (I consider 3 weeks as too long) is a "call-to-arms" global passive buff for the faction and its respective sub-faction that has the least amount of claims.
The (sub-)faction that has call-to-arms buff will grant its players a 5% more damage + 10% more health + 0.5% more luck in the open world AND wars.
These numbers are not absolute but are mere approximations and examples, it’s always up to the Devs and their game designers on what would be more balanced and calculated.
So what do you guys think?