I think there is another consideration: democracy. I say this as someone who was arrested defending Indigenous title to land and inherent right to self-government during the Temagami protest. I accept your description of Canadian law in this case.Band councillors may be voted in, but their "constitution" is the Indian Act as defined by Canada. Band councils may do arduous and essential work for their people, but they are hardly an autonomous voice. Their principal authority is for the distribution of funds granted to the band by the Government of Canada, and being voted in does not make them an independent voice. Band councils have been around for a century or more, but in the end it was the hereditary chiefs who ran the struggle for self government and indigenous title, and who pushed Canada to acknowledge as much indigenous title and self-government as it presently does.
What is NOT clear to me is whether a majority of Wet'suwet'en people oppose the pipeline. Saying the hereditary government has sway over unceded lands may not be enough, as "free, prior and informed consent" could be adduced from the expressed will of a majority of the Wet'suwet'en people -- even if this were to run counter to the will of hereditary leadership. One reason the Supreme Court acknowledged the authority of the hereditary leadership in the Delgamuukw case was because it was backed by "Indian Act" leadership.
I agree with the inherent right to self-government, but let us consider what a nation to nation relationship means. If the Saudi population disagreed with the King of Saudi Arabia, who descends from the 1000-year old Sharifat of Mecca (and Hejaz), would the "traditional" nature of his monarchical rule justify our support for him, or would international standards of democracy have to be preferred? I am not naive -- too often western appeals to democracy have just been rationalizations for imperialism. However, democracy IS an issue. If the will of the people contradicts the wishes of a minority leadership, howsoever traditional, why should the latter's will predominate? Of course, it may be the case that a majority of Wet'suwet'en oppose the pipeline, and many forms of Indigenous government selection are highly representative (sometimes without meeting the one-person-one-vote standard). But the popular will of the Wet'suwet'en also matters, not just decisions of traditional leadership
Surely for the few thousand Wet'suwet'en people, their hereditary chiefs are hardly the remote, wealthy, and heavily armed autocrats of the House of Saud.
True self-government, true title to land, and more directly accountable leadership are likely to come altogether. But expressing doubts about the quality of Wet'suwet'en democracy should not give Canada any kind of right to override Wet'suwet'en indigenous title for our own convenience.
