[Wrana]

They could deal slightly more damage with their slings, reflecting either increased accuracy or better quality of stones. Another major advantage would be 2 mapmove, since they aren't 'militia'.

Professional slingers used lead (or even sometimes bronze) bullets made in a form. Description may mention this as a justification... 2 mapmove would be certainly very useful, I've forgot about it.

I suggest snake themed sacreds because MA Mictlan is based around flying snakes and has a serpent sacred national summon. Crocodiles just don't seem to come into it.

Possibly. But crocodile-skin armor was certainly used in Mesoamerica. And even poor amphibian unit would be a strategic advantage (even if non-sacred). While considering snakes... Possibly poison protection would be sinergetic with sacred Toads - but it would have to be 100% & this could be too good..

Because chariots were present in the early history of Irish warfare and in Dom3 are generally an EA thing.

Well, Ireland is Eriu. And chariots remained there almost until 16th century iirc. Here it would represent more archaic nature of their army which is compensated by magic & inborn high quality of Tuatha/Sidhe warriors. While in EA they would be redundant - Sidhe surely have no problem with most human infantry (& charioters wouldn't get to use their higher weapon abilties, except against other chariots)!

Dogs used to hunt wolves would obviously outnumber them. They were also used to hunt bears.

Well, that's not the case with wolfhounds & other such kinds of dog. They are specialized to be better than wolf 1-on-1 (for wolves, being no fools, will just make strategic retreat if presented with too much dogs), Irish wolfhounds at least are also faster than wolves on the run - for the same reason. They are however, less clever & have somewhat worse health as their life presents more protection from the elements - but this is represented by them having no stealth, but patrolling instead... I wouldn't probably give them supply, but it certainly has a nice synergy with massed archers... At the same time hounds used against bears were used just to draw their attention from the hunter - completely different specialization. In Russian, they were even named differently than above-mentioned type though in English they are both "hounds". Another type of dogs sometimes used to fight bears (but only after bear was already caught) was bulldog-type - still another specialization!

TC are masters of the elements. Ulm aren't even close to that.

Certainly. But as their MA theme is anti-magic, they could get such specialized thing. Probably with Holy requirement? And they sure as hell need this much more than Tien Chi!

Probably possible and a nice idea. I tink I'd make it a poison arrow rather than a tangle arrow though.

Yes, of course snake-themed arrow should be poisonous rather than entangling! I just used an example to illustrate having two kinds of such a spell with different levels. Sorry if misunderstanding occurred.

Another thought: I personally find an idea that Vans or Tuatha would worship a human Pretender somewhat illogical. It would probably be good to give such races Rainbow-type Pretenders from their own kind. Something similar to this is made with C'tis having Saurolich, and giant-types having their own mage-kings as Pretanders. Note that I don't want such Pretenders to be SCs - just mages of appropriate races, with primal paths appropriate to them, human size & racial bonuses... It's OK if they will be more costly than other Rainbows - they just need to be here.