Larger NPC colonies and hoards with balance

[Zombiologist]

I like the idea of small bands of survivors getting together and I think it would be interesting for it to be possible, but very difficult to build larger NPC colonies over time when NPCs are added to the game. I think it should be on par with say Dwarf Fortress where the learning curve for such colonies is steep and very unforgiving of your mistakes, and you'll learn by losing whole colonies at times. In fact sometimes you do so well your colony grows too fast, and starvation sets in while other times it's a war of attrition where dwarves drop one by one or succumb to growing hoards of enemies, and other times still it's something you never expected or planned for coming out of the left field catching you off gaurd. I also think to really catch that Romero zombie feel there will need to be some way to have larger hordes, both for balancing larger colonies and in general. In the Zombie Survival Guide book it expressly warns of how attracting even one zombies can potentially cause a chain reaction attracting more and more zombies from farther and farther away, hundred, thousands, hundreds of thousands, or unlikely but possibly a million zombies, is what the book stated and that this risk increases the fewer other survivors are left to distract zombies from bunching up. I've managed to attract screen filling hordes that blot out the ground with their mass on rare instances and there is something very satisfying about facing such a daunting horde but I find they glitch into SCP style shadow monsters after a while. The only ways I can think think to fix this would either limiting the zombies that can be on screen, but have a cache of off screen virtual zombies that continue to show up as you kill the on screen zombies, or to have zombies that once bunched up and in a large enough group are treated programming wise as a single entity that only breaks up into individual zombies when close enough to a player or otherwise dispersed somehow. I also think the idea of having a thriving colony facing a massive hoard that goes on for as far as the eye can see would make for a very entertaining zomboid experience. This would also be especially terrifying if you in fact did not have a colony but simply had survived on your own all this time to suddenly find yourself the target of countless walking corpses.