I am not a big fan of Herbert...
but I admired the way he created the Dune universe. I assume Dune was the first novel and it was all I could manage to digest. Of course I watched the Mini Series and I was lukewarm on it. It got a little too hinky for me.
His fascination with Arabic culture was obvious. I never connected the Spice with oil but I can see how that works. My mind went off on another tangent, related to the future of humanity as a space-faring culture and the frequent absence of democracy in that culture.
I would also nominate the Russians for the Harkonnen, and the Catholic church for the Bene Gesserit. I have no clue for the Guild or the Sand Worms off the top of my head. I'll have to think about that.