There is actually! However none of the come from Europe but from Asia (and theres a ton of Asian civs to talk about) unless talking about the already comfortably represented Poles.
I have a really thick book about European warfare during the middle ages and I have read it twice. I think I know quite a bit of it so unless you can mention something as a counterpoint. I really have to justify why comparing tribes that didnt do much to powerful long lasting kingdoms just because their conquest was interesting is a dumb idea? The Kanembu were considered one of the most powerful states of Africa being at the same level as Ethiopia and Morocco and were a kingdom that last more than a thousant years with an 800 year long dynasty and an interesting history in general, Nubians fought off the Arabic invasion of Africa, Somalis were able to fight on even ground against an Ethiopian-Portuguese aliance, Songhay were extremely powerful and had an university that made people from all over the world come over for education, the Yoruba and Hausa were majors productors of resources for the world at large just like Mali. The Finns were a bunch of tribes that never had an independent state nor did anything impressive as far as I know.
I havent mentioned a single tribe, I have mentioned a bunch of powerful states with a huge influence on their regions and importamce to the world trade if not important civs on general to the world st large in the case of Somalis. These civs were important in their own way, you just dont get the appeal since most of what these civs did never influenced Europe or Asia.