For all of the umpteen characters in Game of Thrones, Martin keeps some aspects simple. At least in the TV show. It’s House vs. House. He calls the Seven Kingdoms,…well…Kingdoms. Dukes don’t seem to be mentioned. Nor Earls nor Counts nor Barons I think. There are Gods and their followers agendas, but compared to the machinations of The Church in feudal society, it seems fairly simple.
Try explaining Richard II through ‘The Henrys’ to Richard III to a layman.
Almost assuredly real-life feudal societies are more complicated. But in Game of Thrones, there are pretty clearly ‘levels’ of nobility – the King and royal family are on top; the Great Houses in charge of each region (Stark, Arryn, Tully, Baratheon, Lannister, Martell, Greyjoy, and Tyrell) are next; lower ranking lords like the Boltons (which, as of late, have been raised into the equivalent of a Great House as Wardens of the North), Umbers, and Freys; and landed knights (knights granted lands and castles) like Davos Seaworth and the Cleganes are the bottom.
But this isn’t as complicated as real-world nobility, if I understand it correctly.
A reality is always more complicated than any representation of it can be, and real life is always going to be more complex than any fiction can be, if only because both creating and enjoying fictions are parts of a real life.