I'm starting to dive back into this series before the TV show will inevitably fuck up huge parts of it. I started reading this series way back in 1990, and, flaws and all, I love it.
But one of the things I don't think they got wrong was casting a multi-ethnic group of actors. In fact, I think it's a great way of picking up and moving forward with what Jordan was trying to do when he wrote the series.
Here's a
meta on race (no critical spoilers) in WoT from a sadly unfinished series I did for Sequential Tart. (Thank you, M, for creating such a toxic environment at work that I literally did not have the mental energy to talk about one of my all time favorite book series once I got home at night.) Perhaps my revisiting the source material will allow me to finish the sections on sexuality and the nature of evil.
Anyhow, it's really clear that Jordan was trying to create a society where there was no White Supremacy (as we know it) and that, if nothing else, the sheer chaos of the Breaking and "lost" centuries After the Breaking (AB) meant that world populations had moved around as the world shifted. Race was no longer tied to region because those regions literally did not exist.
Jordan mentions specific racial traits for three groups of people: the Aiel (blond, red, blue/green, dark hair and dark eyes being virtually unknown), the coppery-skinned Domani, and the Atha'an Miere, dark skinned, dark eyed, curly dark hair.
We know from the books that the first of the Tuatha'an very distinct racially, but today, because of all the racial mixing they did over the past 2500 years, they look like the vast majority of people in the westlands: Dark hair and dark eyes.
Now, in my head canon, I've pictured most people in the Westlands as looking like they were of Middle Eastern, Latinx, Mediterranean, Slavic, or Northern Indian descent, with occasional concentrations of traits (eg the "honey blonde" hair in Tanchico, or the "tilted" eyes more common in Kandor or Saldaea), but almost everybody is a shade of tan. The red/strawberry hair and blue-green eyes that mark the present royal line of Andor are rare, and distinct in the West.
So, I fail to see the problem with casting an extremely diverse group of actors to be in the series. It's a world where, outside of being an Aiel in the Westlands, or one of the Atha'an Miere far from the sea, nobody's really going to notice, comment, or care. It's continuing what Jordan started.
Matching the exact skincolor/haircolor is only going to matter for a small amount of people:
1) The Aiel. Outside of a handful of cases, they have not intermixed with non-Aiel people mostly due to geographic isolation. They really need to be redheads and blonds.
2) The Atha'an Miere. They have been a sea people for 2500 years, and again, though they are traders, for cultural reasons,they marry mostly amongst themselves. (Hint: there are no wives left behind in ports.) They really need to cast Pacific Islanders, South Indians, and African descended actors for these roles.
3) The present royal line of Andor. Morgause, Elayne, and Gawyn need to be redheads -- for reasons that are explained in a crucial scene in history.
4) Rand Al'Thor. Really, really has to be a red head for reasons that will be revealed.
ETA: Here's a video that takes on the issue and comes to pretty much the same conclusions,
but from a different direction.