I'm honestly not seeing the problem here. The actors seem to embody the essence of the characters. I've always pictured Egwene as dusky. And to those who think this is inappropriate for mountain people, I'd like to say that Manetheren doesn't have an indigenous population seeing how it was submerged in water. After the Breaking, when it rose, it was said to be rich in iron ore and of course, there was proximity to a water source. The people who came there were settlers. Cultural diversity is more than likely.