Could this work?
Question: My novel is set in a land similar to Africa, mostly like the Sahara desert except that unlike the Sahara, this region is almost nothing but sand dunes until slowly working into rough plains similar to the savanna. Anyway, the plot involves a tribal people aesthetically similar to the Zulu at their peak under King Shaka. Two key differences I wanted to make are 1) They live on the sand dunes in the arid desert, not the plains, and 2) I really wanted this tribe to be master horseback fighters, similar to the Huns or Comanche. In the book, the reasoning behind their horses' ability to maneuver on the shifting sand dunes while carrying mounted warriors is explained in that these horses were bred and raised and trained on the sands, and so are perfectly accustomed to the loose ground of sand, putting most enemy cavalry, who would be used to solid ground underfoot, at a noticeable disadvantage. Plus, with horses so used to moving on shaky and unstable ground, raids into the hard-grounded plains would be all the more effective. I admit I don't know much about horses, but all of my research has turned up useless (and really rather annoying) info about horse breeds, diets, a bunch of stuff totally useless to building a plausible cavalry force. Does my tribe sound the least bit possible to you? Does them having such effective cavalry make sense? Just your honest view of the story premise, and any advice on how I can improve it, would be very helpful. Thanks!Answer:
This is more of a question about horses than plot.
I'll confess, I don't know much about horses, but I do know the Arabian horse is a desert breed. You might do some research on what makes them so.
Personally, I suspect things like the ability to survive on little water might be more of an advantage in such an environment. My other question is what these horses would be fed in the desert.
However, cultures and animals generally adapt to their environment, which gives them advantages and disadvantages in other places.