Yeah, agree with Stupac. I'm about 20 years into a Saka campaign (after I got about 30 years into a Saka campaign in 1.0!), and I tend to use my FMs a lot in battles.

As your settlements are going to be fairly poor compared to everywhere else, they don't seem to make very tempting targets to the AI. That means you can get by with very small garrisons, and I generally don't waste FMs on this task.

Also, as you'll probably go into debt quite quickly at the start, you're better off making the most of your starting armies. If you can use them to conquer a few settlements that's great, but attrition can be your friend when you don't have to pay dead horse archers!

I suppose the other thing to get used to (which I'm not 100% on yet) is the different "lifestyle" choices - nomadism, pastoralism, or the client state option. If I've taken a fairly well-developed settlement in a position that's central to a region that I will probably need heavy foot troops then I'll go for the client state option. Otherwise, I tend to use pastoralism where I can (for some limited economic benefits, as well as some roads), and only going with nomadism where that's the only option. Of course, in 20 years time I might completely rethink this strategy...

Even though I'm still very much doing trial-and-error, I've found this nomad campaign extremely interesting, and very entertaining. It's certainly a challenge, and very different from western infantry-based campaigns, but certainly well worth the effort.

Good luck!