When they camp the next area you got time to organize a counter attack rather then just the time it takes to exit the core at a gate.
The Guards have helped levitate some of the issues, Ive managed to trick 1-2 enemy groups into getting slaughtered or run off by them, the problem with those of course is that they de-spawn after they get to their end of patrol route and you have to wait for a new one to spawn.
It would be nice if Guard patrols do not despawn at the gate but go back and forth from set points indefinitely, any lost guard NPC would re spawn at set intervals to replenish the patrol and to give attackers a lull if they manage to wipe the unit out.
Two alternatives:
If the three ZC areas around the gate are owned by the gates faction, it locks that gate off too other factions, giving an incentive for a faction to defend those vital Zones and attackers to take them.
Same as above but rather it doesn't close the gate off but spawns patrols in the neutral zone between the capture zone and maybe buffs the gate patrols.