As I have it thus far:

Human refugees come to this foreign planet where they find two major civilizations - a city-dwelling race of farmers, and a hill- and mountain-dwelling race of hunters who hunt, kill and eat the farmers. The balance of power is maintained because, while the farmers have numbers and superior metallurgy on their side, they are temperamentally unsuited to sending armies forth to do battle. The hunters, for their part, may be faster, smarter and more cunning than the farmers, but they have neither hope nor intention of rooting the farmers out of their walled cities.

And in between them, there is a nomadic race whose ecological niche is "in-between" - they're omnivorous, fast-breeding, fast-learning, and physically very hardy. Not strong, though. They make their living as spies, traders, thieves, and so on. They're also the best apothecaries around, because they share knowledge and experimental results between each other but keep their findings secret from everyone else.

So, the human faction gets embroiled in political debate and intrigue over the matter of how to deal with these three nonhuman sentient species. Are they dangerous? Can they be negotiated with? Can they be walled off? Should they be wiped out? Should humanity try to share its technological blessings with them? Should humanity try to maintain the status quo? How should the human colony maintain its high-tech industrial nature, in this context? And so on and so on.

Central to the story are one recon officer, a battle-damaged veteran who is nevertheless respected by the colonists; a battalion commander who believes leaving human-ruled space meant leaving behind the ethics of human civilization; and a clan leader of the hunters, who shares an unusual bond with the recon officer which borders on magic.

The commander has a plan that involves arming the hunters with modern-day weaponry, in order to provoke a full-scale mobilization of the farmers. The hunters, with help from human advisors, will slaughter the farmers en masse; then the hunters' population will crash as they are deprived of large prey. The hunters' clan leader is neither too keen on rifles nor that worried about the ecological impact of accepting new technologies. The recon officer is strongly opposed to the idea, and in fact wants to have the human colony walled off from the rest of the planetary surface.

Various things happen. The clan leader's unusual abilities play a part, and the commander's plans do get underway to some degree. I'm not sure who will prevail, in the end.

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I have to say that this all came from thinking about designing an RTS game with multiple factions, whose play styles would be very different. The farmers' faction would be focused on maneuvering large formations of heavy infantry; the hunters' faction would be focused on guerrilla warfare; the human faction would be focused on striking from afar. Human troops would be outnumbered even worse than the hunters, and would probably lack their skills in sneaking about and hiding, due to their use of technologies like aerial assault and motor vehicles. I also imagined that the human faction would be without heavier weapons like artillery - their heaviest weapons would be like HMMWVs with machine guns. I was taking some inspiration from the book Guns of the South, in which time-traveling white supremacists bring assault rifles and machine guns to Robert E. Lee.