Also, it seems sloppy to me to have EVERYTHING originate within a single 30 year period: Atreides, Harkonnen, Suk doctors, the Tleilaxu, shield generators, suspensor lights, faster-than-light travel, discovering melange, the Freman, riding worms, the Bene Gesserit... It was almost like the authors had a checklist of references they wanted to make, and because it was set so much earlier they thought they all had to originate and none could be already established.