Lucas stole primarily from the Hidden Fortress and John Carter. And Martin is primarily stealing from European history. But certainly Dune is an instruction manual for writing a HUGE story.
Well let’s see.
Arrakis - Desert planet; Tattoine - Desert Planet
Sardaukar - Dune; Imperial Storm Troopers - Star Wars.
Chani, who is ‘married’ to the one, Paul Maud’dib, gives birth to twins Leto and Ghanima then dies.;
Senator Padme Amidala (aka HDRC), who is ‘married’ to the one who will restore the force, Anakin Skywalker, gives birth to twins Luke and Leia then dies.
Dune - Duncan Idaho; Star Wars - Hans Solo
Dune - evil relative Barron Harkonnen; evil relative Darth Vader.
Dune - Bene Gesserit ; Star Wars - The Council.