Just why are the Hordelands dominated by human tribes and cultures? Realistically, the more monstrous humanoid races of the Realms, long having been characterized as able to thrive in such harsh climates, would probably vastly outnumber any would-be human colonizers. The Doylist explanation is, of course, that TSR had an authorial mandate to make humans the dominant species in any and all of their settings, to the point of outright addressing Games Masters in the Dungeon Master's Guide and telling them that they "should" be creating worlds with humans as the dominant racial power too.
