I'm not going away until someone gives me a really GOOD argument. The fact that they are not in historical sources, is only a good argument for the northern arabians. Lack of written evidence doesn't mean it wasn't there. Especially with the saba. Southern Arabia was too far away for the persians and the greeks. they only went there to trade, there were no military expeditions into the south of the arabian peninsula. My point is that those people who might have used camels for battle tend to be nomadic, and live in very inhospitable territories no-one but them is interested in anyway. They were not interesting enough to write much about, and writing wasn't exactly a top priority for those that lived in the desert. The northern and southern arabians might have been kin, but culturally and linguistically they were very different. The southern arabians spoke another language (though both were semitic languages) Northern Arabians were also far moer heavily inflyenced by those who lived around them. For large parts of the time they were under the rule of a different people, and when they did have independent kingdoms, they either did not last very long, or were vassals to the dominant powers of the middle east (in this case the ptollies and the seleukids) . Southern Arabia on the other hand was an isolated mercantile powerhouse. They shipped goods from India, and traded them up and down the red sea, or shipped them across the deserts in caravans. The region had natural resources in the form of frankincense and other aromatics as well. They had contact through trade with the dominant cultures of the time, but it was limited to trade over large distances. Though the southern Arabians did write, most of this writing has been utterly lost because they did not have durable things to write on (they wrote on dried palm leaves for example) and only tiny fragments of those texts remain. Camel cavalry could well have been used there. As I said before the saba historically never went further then southern Arabia and ethiopia, so no one would have known much abot their military either. They might well have used Camels in battle without anyone else knowing (or really caring for that matter) once you get out of the south of Arabia and Africa, you are already being ahistorical, so why not let them have camels. It is plausible they used them, and it would make them even more fun to play with.

Camel cavalry need not be abundant in any case, since it would be bedouins fighting for the saba, so maybe only a few arabian province (and perhaps a few african ones as well) have them, because those provinces have a larger amount of bedouins living in the territory, this would make perfect sense I think.