Further, let's say that these animal cards must be played from your hand, and once played on the totem they are now "out of the game". If the animal cards can be played for some other (beneficial) purpose, then this creates the tension between playing the card to get stronger vs playing the card to make progress towards victory. Progress towards victory weakens your deck by removing good cards from it. This is (in my opinion) a desirable outcome because it adds tension.
The next step would be to figure out how to get animal cards into your deck, and what else they can be used for once you have them. You've written extensively about hunting, so let's go with that. When you successfully hunt an animal, you add that animal to your deck.
So how do you hunt an animal? You've written about the chaos/harmony/coup tracks, so what if these were also expressed through cards in your deck rather than being a separate thing? The Bear might require "3 Chaos", so you have to discard cards worth 3 Chaos from your hand to successfully hunt the bear.
So how do you get Chaos/Harmony/Coup cards into your deck? I'm not sure, but it should probably involve one or more of the other elements you want (worker placement, raiding, building, etc) rather than being another new element. Or perhaps each card can be played either as an action or as its element (Chaos/Harmony/Coup).
And what else can the animals be used for besides building the totem? Again I'm not sure, but it should involve the other existing elements. Perhaps it's based on the animal, such as Bear gives +1 War, Snake gives +1 Raid, etc. Perhaps you can play animal cards during your opponent's turn to oppose their actions or make things more difficult for them. Perhaps you can play (discard) animals in order to buy other powerful cards (e.g. discard Snake to buy Poison Arrows).
Combined with my earlier expressed preference for limiting the number of "buy" options in deck building games, let's say the basic turn sequence is as follows:
- Play cards from your hand to take actions (played cards go into your discards)
- Flip 4 cards in any combination from the decks in the center
- Discard from your hand to pay the purchase cost for as many of these as you want
- Add the bought cards to your discard pile
- Discard any remaining cards in your hand
- Draw your hand up to full (reshuffle your discards into your deck if your deck is empty)
This gives you some choice over your fate (you could flip lots of Build cards if that is what you want to focus on), but also some randomness and minimises analysis paralysis. It also creates a choice between playing cards as counters during your opponents' turns (this is why the draw phase is at the end of your turn, not the start), vs using them to take actions, vs saving them to buy better cards at the end of the turn.
I like that a lot. Streamlining so there is no need for another system. You can still have a "tech tree" Just have a tribe deck with specifically chosen "boosts" that require Chaos/Harmony/Coup. Not sure about that one. But yeah, drawing four from different decks coupled with the purchasing is perfect.
I am thinking of all the possibilities where I can combine elements into decks to streamline some. The way I think it might work for the deck building is similar to what you have already mentioned. Unlike Dominion though, I think it would be okay to keep as many cards in your hand at the end of your turn instead of having to discard them all to your discard pile. This would enable you to form a short strategy to whatever action you are wanting to do next turn. For example, if you have an attacker moving into your hunt tile or territory tile, you might want to save any defense and counter-attack cards for next turn. So you might only want to discard only a couple cards on a turn and then draw two to end your turn.