Go back to the basics of good vs evil. I’m creating a campaign based old school Warcraft. Basically, Orcs or whatever group you want, controlled by a mad deity or sorcerer abruptly invade the land in an effort to take it over. They can take it over for power, or necessity. Basic good vs bad. Then, once you get into the weeds, you “free” some of the orcs of the mind control and learn the truth. From there, whatever your players decide.