The Back of Beyond book includes only army lists for Contemtible little Armies. It's are written by Chris Peers, so as with most of his rules they might work well if you're able to understand them. Don't get me wrong, they sound good enough to me, but without help from someone who knows them it's really hard to get into them, as they aren't very well structured.
But I'd say that even on its own BoB is worth a try, as you can use the army lists with other rules sets with vey little work and it's a great guide to who was involved in the central asian chaos.