Hear me out, what if we add hordes in a new way.
Every guild territory now has the chance to get attacked by NPC's. Whether these will be zombies, bandits or something else doesn't matter. This way hordes aren't affecting low level players and are a late game feature only. The guilds now have to look out for NPC's attacking their territories as well as other players. Maybe a feature where the players can fight a horde of mobs to defend their territory from NPC's is a good addition to this.
