Which is where? It seems to me that Kurds come from a heterogenous background, with much of it traditionally nomadic, and not really anchored to a single homeland like some other groups in the region (like Assyrians and Jews). The Kurds probably have areas that they've lived in for a long time, but it certainly doesn't include the full extent of modern Kurdistan. For example, Kurds didn't even become the dominant ethnic group in Arbil until the Middle Ages (or later? That's when Assyrian dominance decreased), and now it's the capital of Iraqi Kurdistan.
I agree, we find them from Phrygia Gordium to Arabic gulf, and North Iran,
that means movable inside limits, followinf something, their breeding stock or moving army tribe,
I believe the second, we find them also in ancient Greek literature doing the same, probably they were a specialized army that learned a kind of war trick,
I believe they were a hammer of Kings or Satraps in area and they mixed when a new 'army' tribe connects with them,
from 1900 till today we see the same hit and hide that did in Xenophon, and hit and hide even among them according who foreigner chief like,
I believe that kurds comes from an ancient nation somewhere middle east and Iran that created something, a big city or a culture, lost it, and learn to live defending in nomadic form, while in many times they served as army chieftain to some kings, and they accepted other war tribes among them like Skudra- skudet.
cimmerians is still a mystery cause are connected with Thracians, which are connected to gothic, slavic, para Greek, and Iranian,