Obviously it's not fitting for every example, but I actually think Steppe Cities should feature as a representation of Absolute dominance Nomad Camps. Basically it should be the approaching the peak of having nomad camp, requiring tier 4 and tier 5 Dominance. To my knowledge, most "steppe cities" like Sarai would be the centers of nomadic Empires(the Golden Horde, in Sarai's case). Indeed Sarai IIRC had a considerable nomadic element with huge numbers of tents. Basically, these steppe-cities relied on being the centers of a network of tribute and trade in order to ensure their place on the landscape(though they did exploit the land around them as well, ultimately if not the center/benefitting from a state, they would fade away). As such I'd have it so that at at least T4 dominance, or whatever Dominance level the Khazars start at at least, you can choose to turn your camp into a city, giving it a proper name(rather than just "Khan X's Camp", new buildings options and more powerful buildings, Many tent buildings can remain but now you can also establish grander buildings/districts for your nomad capital.