Ultra-tough, misunderstood desert cultures can be a slightly overused trope in fantasy writing, especially alternative world fantasy. They often crop up as the much-needed army for the beset hero, at just the right time, after the hero properly impresses them and meets some ancient prophecy. It might be that the origin of this tendency lies with DUNE.
Well, I've finished my read-through of the first Fo'Fonas novel (current working title is At the Top of the World). I've made extensive notes, and will be combining my own notes and changes with the feedback I get from my various test readers to inform my revision process. Some of the major changes that I'm currently tracking are