From what I recall, the Sardaukar were mercenaries who were recruited from the strongest survivors of the prison planet. It was an interesting utilization of the consequences of Darwin's theory: only the strongest survive. The reason why the Fremen defeated the Sardaukar was because Arrakis was an even more hostile place than the prison planet and the people who survive there are more ferocious than anything else in the Dune universe. So: Fremen > Sardaukar And yeah the Sardaukar were feared... but that wasn't wholly because of what the emperor made them do. They were hardened criminals. That is the scary part imho: Hardened criminals and psycopaths being recruited into the army that is used to quell uprisings. What fun! I never expected to pull out my geek card like this on t.m.o.