[myxomatosii]

There is a whole ogre/troll city in the foreign quarter which is right inside of Neriak, ideal city for ogres.

Plus Nektulos is one of the best starting areas in the game, guards spaced throughout the zone equally, two undead camps, many halfling camps (for evils), lots of tree snakes near the path fork at the undead pyramid, and connections to EC to sell and Lavastorm (13+) for Najena (10+).

But yeah, as far as the lore I think dark elves aim to manipulate the ogres and trolls into a sort of civil war between the races of Rallos Zek and Cazic-Thule, therefore to further their goals they tolerate the large races. Much like the orcs of Crushbone.