Warhammer 40k = Emperor's Children(CSM) and Orks.
Brush Fire: Historia Rodentia= Aquitar, Vandalands, and Ribenguo.
Orkish Republics:
Closest historical equivalent is chimpanzee extended family group, warband and Banana Republic, where the Generalissimo is President for Life, while keeping a close eye on ambitious subordinates and competing interest groups and inter tribal rivalry.