The Emperor did have his Sardaukar after all (Later, Leto II would have his Fish Speakers as his own personnel). Paul Atreides also co-opted the Fedaykin (a group of Fremen guerilla fighters) to be his personal guard & elite death-commandos. Also we have the Ginaz sword-school. And perhaps also Tleilaxu Face Dancers I think count as an example too.<br/><br/>However as afaik, House Atreides as is nor House Harkonnen had specific names for an elite fighting group. Still, there are enough examples of a House having a specific named group they hold dominion over.<br/><br/>I still haven't looked over the roles yet, will at some point soon though.