After having delved into the Empire's background with the provinces and the old world, it seems to many that many of the other races of WHFB have superficial background. For example, the Orcs and Goblins are just stupid steppe dwellers. The Dark Elves are murderous sadists, and all of Naggaroth is just frozen plains with variants of Dark Elves running around murdering each other with little politics, factions or variations on that theme.
So my question is: Is the fluff for other races indeed superficial, compared to the Empire? If no, where can I find more in-depth fluff for other races?