With this kind of game, I don’t see how co-op would be achieved, at least not in a way that would be fun. Working off the idea of each person having their own “Kingdom Map”, allowing someone to gift a tile to a “friend” to allow them to build an outpost (of sorts) would, in my opinion, be the only way to prevent people’s builds from conflicting with one another. Otherwise, the two people would have to always be playing at the same time, or it’d create an imbalance in the mechanics.
For PVP, I’m going to reference my reply above:
Refer to my RNG thoughts above.
This could be heavily exploited and create a major imbalance. Say I’m not the player to keep restarting and instead build my capital from what I’ve got. I hit the world stage and go against someone who’s restarted so many times, they basically started building a city with more than I have now. To me that would feel like a cheat that’d be providing a bit of a decent advantage.
I’d love to see a game with that many Hearthlings, hell I’d just love to see pathfinding try to keep up with that. But at that point, you’d have to have some filler population, and I doubt they want to do that.
Even at 20 'lings, people don’t remember all their names. They may remember one or two, but beyond Old Man Jenkins the Farmer, or Leeroy Jenkins the knight, people aren’t that attached to them now. So even if we had 200 in one city, or 2,000 across our empire, it’d be the same IMO as to whom we remember.