Being savage and being dumb aren't the same. The Orcs are simply aggressive by nature. For example, people might say that Saurfang Jr was an idiot for charging at the Lich King like that. But people fail to realize that in most cases Orcs win with that tactic, heck if Saurfang Jr had his fathers axe then he would've killed the Lich King on the spot.
And what about Gul'dan and Ner'zhul, were they idiotic savages as well? They were masterminds.
Durotan, Orgrim Doomhammer and Thrall are quite smart as well.
I think you are horribly biased. Not every Orc is a peon.