FWIW, IMHO there’s no chance the Hurrians and the Scythians were the same folks.
The Scythians were as literate as most groups of their time:
http://en.wikipedia.org/wiki/Scythian_languages
Where Did the Scythians Come From?
"Evidence of one source of Scythian origin does consistently appear and reappear both in the study of linguistics and in the archaeological and written record. That source is in the present day area of Luristan, in Iran. Anciently this area was occupied by the nomadic horse riding people the Medes (who were later part of the Persian empire), and the Cimmerians, a people who appear to either have been identical with or closely related to the Scythians. Artifacts from Luristan appear to be strongly Scythian in character. Researchers have concluded that a treasure found at nearby Ziwiyeh was from the tomb of a Scythian prince. (Ziweyeh was located in an area once called the kingdom of Mannae - an area eventually overtaken by the Scythians.)(1)"
"Luristan also shows strong links with an area between the Black Sea and Caspian Sea known in ancient times as the kingdom of Urartu. Urartian (also known as Hurrian) art in turn shows strong links with the art of Syria and Phoenicia. (2) Its colorful style (using enamel and stone accents in their metal work) is a departure from the art of Assyria and Babylonia but more in keeping with the inlay style of the Near East and even that of Egypt. (3) One researcher, K. Jettmar, lists the different treatments of animal forms in Scythian art that come from the Near East.