Oh please, at the first bad harvest--because neither the residents of Corntown or Flintstown ever met Guntown to trade their surplus with them--the overwhelming numbers of Grainville launched human wave assaults on the prosperous but few Flintstown people, slaughtered them and sent their corn stocks home, and then cowed the moderate people of Corntown into submission.
The people of Grainville lived pauperly ever after on the annual tribute from the people of Corntown, who gradually devolved into even poorer people because they had no incentive to excel and because they were under the deadening watch of Grainville, which feared that somehow the people of Corntown might become a new Flintstown if left alone.
Flintstown was an archaeological dig, of course. Nobody knew how they built their huge grain silos--or why they built them. Just what would they put in them, anyway?