Why are there no Sarmatian invasions during EB's period?

[Jolt]

There are many other "productive" things that can be grown in mountainous regions. I'd not consider Iberia as a good example since they're not highly developed like romans or parthians.

I'd appreciate you enlight me as to what can be grown productively in mountainous terrain with the agricultural techniques of the classical times? Wheat? Vineyards? Olive Trees? Barley? I do consider it as good enough example as any other. I don't see the Romans building many latifundia in the Spanish Meseta or in the Mountainous Northernwest, despite their "high development".

Yes, but there are other invasions you know ;) If parthian had the same populations, can they possibly afford like 500,000 professional horse archers (the number of full-time legionaries Roman can afford to, if not more), while maintaining the same living conditions for its citizens?

I didn't really understand the meaning of this one. Other invasions? Population the same as what? The nomads? (I suppose the Partho-Persian population was significantly bigger than the nomad population), and as I said, the cost of maintaining an army is a very subjective subject. Still, as long as they had the money, they could hire nomads, as I have said. While maintaining the same living conditions for it's citizens.

I wasn't arguing about their effectiveness against nomads, because they probably had no alternative (they had no crossbows :P). But since they're not nomads and they don't live by hunting, HAs and their horses must be very expensive to train and to maintain, compared to other types of troops - whether the government pay them or not, cost exists whenever you have someone who's not doing farming or other works.

As I said, the Horse Archers aren't farmers or merchants. They're either the noble class, who normally would practice it, or nomad mercenaries. (Heck, I'll give you an example I know. Alexander was having trouble during a rebellion in Baktria, by one Zoroastrian man named Spitomenes. Since he had no mobile force to counter the rebels, who I supposed used nomad tactics, he hired the Dahae, which are a nomad tribe, to crush the rebels. There wasn't someone being pulled out of farming or other works because of this.)

I still am trying to figure out why are non-nomad horses and their riders more expensive than nomad horses to maintain (Because there is no such thing as large contingents of settled Horse Archers, except for the said nobles). And do not be fooled by the conotation "Settled = Farming". Many settled populations practiced both farming and hunting (When able), not only in Persia, but basically everywhere.