It's not, because if we take more crab, they take more elk, or if we take more salmon, they won't submit is on their permit (but will go to BIA solo)....Meaning there is no simple apples to apples negotiation on one topic, everything is all smashed together in an endless spiderweb of confusion.

For example, if just balancing the scales on such a simple fishery as this could be achieved, why haven't they?

Because, as is said, "Payback is a bitch."