Like 99.9% of what we know about how Arteides rule is Brian's descriptions of Caladan before the family moves to Arrakis, it's by and large a quite tranquil world. Quite agricultural but the people certainly don't seem to mind their rulers, on the contrary they adore them.

And yes of course feudal rulers draw their armies from their fiefdoms. Everyone of them does, that's not what makes a feudal ruler better or worse than another feudal ruler: You become a Harkonnen soldier because you like the opportunity to abuse others, you become an Arteides soldier because they're just so fucking noble and just, that is what makes the Arteides better. The Fremen situation was not really any different, though of course boosted by the Bene Gesserit. Or, let's put it this way: It takes an amount of nobility to actually trigger a messiah prophecy. The Fremen are not without agency, here.