I don't think either of them should even be in there. Even the Iroquois shouldn't count. I like having an "India" so that Gandhi can remain a leader, but an earlier dominant culture seems like a nice addition.
I reject the CSA, Ireland, Scotland, Canada, Australia, New Zealand, and Bulgarian out of hand. The CSA is ridiculous, Canada/Australia/NZ are all too close to Britain, and Ireland/Scotland I think are too dominated by Britain and also sort of represented by the Celts.
"Polynesia" and "Serb" are okay ideas, I think, as representations of a geographic area that is otherwise not represented. "Serb" is no better than "Croat" or "Bosnian" or "Albanian" but it would be a nice addition.
I really like the following: Vietnam (to get another SE Asian culture, prob. Ho Chi Minh), Sweden (Gustavus Adolphus I suppose), Poland (whoever, the apparently numerous Poles on this board can pick one), Austria (Maria Theresa?) and Hebrew (King David).
The rest (Brazil, Mexico, Tibet) are kind of marginal. I can't think of a good leader for any of them, and I'm not sure how separate they can be from their parent country in the case of Brazil/Mexico.
I know nothing of the Congo, Hittite, Uighur, Hun, or Assyrians, so I won't comment.
Anyway, I think those new leaders should try the remaining combinations:
Charismatic/Creative, Protective/Organized and Philosophical/Industrious.
I would say Pro/Org would be a great choice for Maria Theresa, since she's mostly famous for reforming and centralizing the Austrian government. It would be pretty easy to make a Pancho Villa for Mexico who was Charismatic/Creative, and... I have no idea who is Philosophical/Industrious. Honestly Mao leaps to mind, and then you could give protective/expansive to Casimir III of Poland.
As for King David, honesly he'd be best off as Spiritual and maybe Charismatic or Creative. Ho Chi Minh would be Charismatic/Organized, and then Gustavus Adolphus would be Aggressive/Expansive. Maybe you would use Songtsen Gampo for Tibet, he should probably be Spiritual/Creative.