What about Jackals?
We have Vipers.
We have Khans. (Huns)
But no Jackals. Yes...they can be one of the raider group inside the Huns's alliance. But they can also be the Spider of the west. The Spiders is a tiny country, not a minor but a micro who purpose is to make some difficult to Manitou Tribes. You can have a Jackal country with 5-8 IC near the Pioneer's Alliance to give an early war. In the west we have only Kurtz's Camp as a minor dangerous power....and Kurtz isn't a pushover!
About flavour. Khans were the bigger raider group. Vipers were smaller but had some glory since they killed some Bos. Jackals are the weakest but they are quite interesting: they are cannibals.
I would see the Jackals as a group with a start stronger (but not much) than the Spiders, but with less chance to grow. This should reflect how desperate is the faction.
Have you ever tried playing with Spiders? They are extremely fun