Wait. You’re saying the Mitanni were Medes? I thought they were related to the Hittites
The Hittltes weren't a single people, the their archive in the old capital showed two major languages were widely spoken. Also, the name is bogus, saddled on to make the "Forgotten Empire" fit with the OT. And their era is similarly out of joint.
The Mittani arose within upper Tigris/Euphrates Mesopotamia, principally along the Khabur River — which explains both its relation to the Hittites and isolation from the Assyrians.
It’s easy to forget the extent of this region. The distance from mouth of the Euphrates to modern Ankara in central Asia Minor is almost 1400 miles.