This question has been bothering me a lot lately, but then I realized it was my own colonial mindset that was getting in the way. Why should I expect Canadian indigenous groups to form a basis of unity so that supporting them isn’t so problematized by the various forms of complexity and difference between different groups? The problem is with the very category of “Canadian indigenous” – it doesn’t mean very much, primary indigenous identification in Canada is with the specific indigenous nations not with the collection of nations that were colonized by “Canada”. While many useful comparisons can be made between Canadian and Zionist colonization, it is much less useful to compare the ways Canadian indigenous groups responded to colonization politically with the way Palestinian indigenous society formed in reaction against the settler colonialism that threatened them.
There is no generic “indigenous solidarity”, there are only specific instances of indigenous solidarity. You can’t express solidarity with all indigenous struggles, because it’s possible that some of those struggles conflict with each other. What you can do is learn about the specific struggles of different indigenous nations, and try to support them in ways that advance the cause of freedom and dignity for all peoples, and which oppose the cancerous evil that is imperialism and colonization.
This doesn’t mean that it isn’t a good idea for indigenous groups to form collaborative actions and when possible a basis of unity. And it doesn’t mean that all indigenous struggles are revolutionary – if a struggle is based on the preservation of a heritage, and is not aimed at the overthrow of what is essentially imperialist about Canadian society, then it’s quite possible that this struggle simply isn’t revolutionary. In which case it makes sense to support it only on humanitarian, rather than political grounds. Political support should be directed towards those struggles which are of both real and symbolic value, struggles which point towards increasingly universal forms of instituted freedom, struggles that aim at what is rotten in the colonialist mindset.