The set-up of Frank Herbert's Dune is what you should be stealing from. Although it's got a ton of worldbuilding and detail, the basic set-up of Dune is pretty simple and easy to reskin to suit just about any campaign setting. The conflict in Dune revolves around six competing factions, each of which is easy to scrub of specificity and refashion.
Here's what Dune has and here's where you get to play with the ideas therein:
- House Atreides & House Harkonnen
- The Bene Gesserit
- The Fremen
- The Padishah Emperor
- The Spacing Guild
So You Need...
- Two noble houses with a long-standing hatred of each other that will inevitably erupt into violence
- A religion that masks its political power in the guise of spiritual guidance
- The unaligned tribal military force that exists outside the structure that defines the place of the other factions
- A powerful military force that defends traditional power structures and the interests of a distant ruler
- A mercantile force that masks its political power in the guise of pure economics
Notice that each of these groupings represents an approach to political power: the power of aristocratic title, the power of religion, the power of the nomad, military power, and economic power. Create factions that represent these groupings of political power, make them compete for a limited resource, and let the sparks fly. Now you've got a powder keg. Hand your players the match and see what happens.