Btw, your perception is a good one. McAvoy's character is named "Leto" or "Leto II" (to distinguish from his grandfather). Leto's twin sister is Ghanima. Ghanima means "spoil of war" in the Fremen language (and is the same in our Arabic), as she is the daughter of Paul and his concubine, the Fremen Chani, who was Paul's love match and not his "official"/courtly wife.

It would not surprise me to find as well that Herbert was playing with words and that "Ghanima" was meant also to imply "Ganymede", the most beautiful of all mortals who was made Zeus' cup bearer. And is also Jupiter's largest moon. Paul is Paul Atreides. Atreides = Atreus, King of Mycenae. The Harkonnen should to my eye be viewed as the Family that represents Cronos/Saturn/Satan, and the Atreides the Family that represents Jupiter/Japetus... the Sky Father. Indeed their heraldry includes a hawk. I see this as a hat tip to Jupiter, Zeus, and even Horus of Egyptian mythology. All the same entity. The Song Remains the Same.