Purpose of Pastoralism for Pure Nomadic Factions (non-Pahlava)

I am currently in a Sauromatae campaign, enjoying harassing infantry-reliant nations and close to wiping out the rival Saka from the map. Anyway, as the title states, I don't see the usefulness of installing Pastoralism in Nomad or Mixed province regions. Since the purpose of playing nomadic factions is to use mainly horse archers/heavy cavalry compared to settled nations, the only gains I see for Pastoralism are walls, roads, and weak infantry while losing the ability to create horse archers. For the non-nomadic/mixed regions, Allied Settlements would be much more useful since I will be able to use the Local MICs, which will provide better quality infantry in which the Sauromatae really need while losing the ability to use noble cavalry. Unless there's something that I don't know about, should I be building Nomadism in all nomadic/mixed regions and Allied Settlements in the non-nomadic/mixed regions?

This right here is a play-style choice. PLUS the fact that the pure "nomad" resources are in a limited number of provinces.

EDIT: This also represents the natural expansion and learning of the steppe nomads from other factions. You can make Rome be a nomadic province.

I think pastoralism is really usefull because you get markets and farms, which generate additional income, thats really nice since sometimes its not posible to be getting money from raiding towns, most of my towns have nomadism though but i also have several towns with pastoralism and it helps to get some extra income, and well u dont get only weak infantry u can get those voinus and the scythian axemen that have the armour piercing ability and can be useful, anyways like the other poster said it depends on ur play style my friend, but right now im also playing a sauromatae campaign and its important to have some settlements that can generate a solid income, hope this advice helps!

Wouldn't towns that have gold/silver mines be more efficient than building up towns with pastoralism? It's really hard to generate income with nomadic factions other than conquering many settlements or settlements with mines/ports.