Other than the whole "stores water in a hump" and "has feet that can actually deal with sand" things, nah, I can't see a single advantage that a camel would have over a warhorse in a desert setting.
Aside from the fact that the warhorse in deep sand desert would move like an epileptic monkey with rocks in his diaper and die of thirst in a few days, whereas a camel would not.
Which I'm pretty sure arn't covered in the stat blocks for either creature. *shrug*
^_^