Hiya!
One element of the series that I find a bit awkward from a world-building sense, is the hodge-podge multiculturalism. I have no issue with the showrunners making it (far) more multicultural than in the books, but as a world-builder, the lack of any internal consistency is annoying.
I was
just going to post my thoughts about this myself.

I binge watched the season on the 23rd/24th. I also was expecting to see a wide variety of human-types (in every way), and was looking forward to seeing how the producers saw various people. But when watching it...I was honestly confused and couldn't keep track of who was who, who was from where, who was who's wife/husband or mother/father. Quite distracting, taxing and really REALLY pulled me out of the suspension of disbelief.
This continued for a good 4 or 5 episodes (about half the season) until I at least had a grasp of who the 6 or 7 main characters were.
The only vaguely consistent element that I've seen is that Borderlanders seem to be Asian.
Agreed! That threw me for a loop. I had trained my brain at that point to accept that there was no "actual people/cultures with shared characteristics"...then BLAM! "Well, except for the Asians. They all look alike...mostly..." LOL! As someone with the last name Ming, I found that amusing (even though I don't really look Asian; my dad does when he laughs; my grandpa, great grandpa, etc...yup...definitely Chinese). Probably wasn't supposed to be though... I have a bit of a dry/dark sense of humour I guess.
This could be developed in an interesting way, if it was implied that they migrated from Shara at some point in the past. But starting at the beginning, the Two Rivers looked more like contemporary Brooklyn than it did an isolated mountain region set in any part of the world. Meaning, it isn't that it didn't look like Scotland; it didn't look like the Andes or Papua New Guinea, either.
Yup. Confusing and jumbled. More like a haphazard conglomeration of survivors from a world-apocalypse forced to live together than a tight-nit community with a shared history. I just didn't buy it I guess.
What I think they should have done is decide on different regions of the continent having more specific ethnic characteristics, modeling them after real-world types, if only for the sake of drawing upon pools of actors. They could still have Nynaeve be played by the same actress given her origin as coming from somewhere other than the Two Rivers, although Egwene and Perrin would make less sense, or at least require a bit of alteration to their backstories. Again, they only really did this with the Borderlands, and maybe Siuan Sanche and the folks of the south (Tear, I believe).
And don't get me started on Rand's mom looking like a Scotswoman....a pale-skinned desert people? Hmm...
Again, I concur. As I stated above... "not a location of people with a history....more like a rag-tag fugitive fleet of people forced to settle in some area".
Maybe they could have done some explaining as to why Two Rivers was so 'multicultural'. Maybe we'll get something like that later. They had an opportunity when they did the 'flashback' to the last Dragon (Ep 8 ), with a thriving city with flying vehicles and everything.
That said... I did enjoy it overall. I don't think anything stood out to me as "...ugh... why...?". Then again, nothing stood out to me as "...ooohh... cool...!" either. Probably because everyone seemed to be haphazardly tossed together, mixed up, then thrown randomly to the winds...then the DM just rolled some random dice and looked on a "human races" table for each character, regardless of any consistency. So...hmmm...
I give it a solid 6 / 10. Entertaining, some neat stuff, but nothing very memorable or surprising. I mean, Nynaeve dies...but that's ok, she gets better 2 minutes later.

They had a chance to make it at least memorable...but they chickened out.
^_^
Paul L. Ming