The Cadusii (the tribe which may be the potential origin of the proto-Vikings from Azerbaijan) and other ancient tribes in Northern Media may not have been Aryan or of Iranian stock:
Josephus relates the Medes (OT Heb. Madai) to the biblical character, Madai, son of Japheth. "Now as to Javan and Madai, the sons of Japhet; from Madai came the Madeans, who are called Medes, by the Greeks" Antiquities of the Jews, I:6.
Other ancient historians including Strabo, Ptolemy, Herodotus, Polybius, and Pliny, mention names such as Mantiane, Martiane, Matiane, Matiene, to designate the northern part of Media.
We can see how the Iranian element gradually became dominant; princes with Iranian names occasionally occur as rulers of other tribes. But the Gelae, Tapuri, Cadusii, Amardi, Utii and other tribes in northern Media and on the shores of the Caspian may not have been Iranian stock. Polybius (V. 44, 9), Strabo (xi. 507, 508, 514), and Pliny (vi. 46), considered the Anariaci to be among these tribes; but their name, meaning the "not-Arians", is probably a comprehensive designation for a number of smaller indigenous tribes.
and here, it informs:
The Cadusii, a people not belonging to the Persian race, who dwelt in the frontier hills of Media, towards the Caspian, were perfectly unsubdued; they were the ancestors of the bold Delemites (in the heroic epic of the Persians, the Cadusii were called Delemites ...