I think you are approaching this problem from the wrong angle.
First, forget about inclusivity and simulationism for a moment. Make up your mind about what experience you want to create from a gameplay perspective. What aspects of country management do you want to simulate? What situations do you want your player to experience? A good tool in this conceptualization phase can be to write player stories. Describe the events of a typical game session as you imagine it from the perspective of the player.
Then check what occupational groups you need to create that game experience. You will now see what dividing lines make sense in the context of your particular game and which do not.
When you start prototyping your game, try to keep it as simple as possible. Start out with the bare minimum of groups you need to create the experience you are looking for. Don't worry yet about your game not having enough gameplay breadth - feature creep will set in later anyway.
I am looking forward to playing your game.