The developers need to lock one starting zone per faction, the reason is that if players come in, they mindlessly just join the faction with the most territory. This becomes self evident that this faction will always have the most players. Why would a player join a faction with zero territory? Maybe if they read the storylines and actually played the game but 99% of people do not read any of the story lines, notes found in the world, etc.
This will help ensure that all three factions at least stay on the board and have one place they can always go back to for additional perks with mining, etc.
Good luck with your game.