Quote Originally Posted by the_handsome_viking
From their perspective rome was the light that set ablaze the uncivilized world, and unfortunatly these men were so influential that to this day most people will look at you funny if you say something like "the romans took their helmet design from the gauls" or "celts had chainmail before the romans", because it challenges all that they have been taught.
No kidding, you have no idea how many times I had to correct my Art History teacher on her incorrect "teachings" of the Greeks and Romans. Ignorant dofus... she said the Parthians were Mesopatamians.

And as Ranika pointed out, many "barbarians" have advanced military thinking (though this may not be a good thing per se, it certiantly shows sophistication).
The predomonace of cavalry and many related inovations (saddles, heavy cavalry, stirrups, etc.) were pioneered by steppe peoples (and then taken up by other "barbarians", then finally adopted by the "civilized" peoples.
And the order and complex manuevers of many steppe armies far surpuses their civilized contemporaries, which came through not so much training as the life of the steppe and the fact that their leader wasn't just an elected official or someone who came to it by birthright, but also the fact that they had to be the best there was to keep their leadership position.