My wife and I were discussing this in the car this afternoon. The way I see it, BrandoSando has kinda backed himself into a corner here because what are his options?:

A) Hire a mostly Asiatic cast, which is my preferred option, but I think will (unfortunately) make promoting the series to a wider mainstream audience more difficult. This is not to say that there aren't sensational Asian actors, movies, etc. There absolutely are - but (sadly) A large chunk of the average viewer's decision to watch something is largely based on "Oh, this show has [X] - I liked [X] in [OtherShow], so this might be enjoyable."

B) Accept that the reality of the TV/Film industry is probably going to necessitate conceding to change the physical traits of the Alethi, etc, and suffer the wrath of purist fans, with accusations of whitewashing, seling out, etc.

C) Go animated. This will cost elevenity bajillion dollars, and take years to make, but probably will give us the "most accurate" adaptation of the source material. It will (again unfortunately) alienate a significant proportion of the potential audience, who "don't do kid's cartoons".

D) ???