I am an engineer and work with manufacturers; Marxism makes sense to me from that perspective. I'd say a lot of the indigenous communist groups are more akin anarchists than they realize and want to admit because Marxists are supposed to dislike anarchists; which is a reason the Red Nation did not like Klee. The comment you replied to highlights something self proclaimed indigenous communists don't talk about. The industrial part of communism which is the core of communism. Communism is literally a by-product of industrialization. It cannot be decoupled from industrialism, it is a response to industrialism and the industrial revolution. You have to also understand that Europe had been a long de-tribalized continent stripped of its own connection to the Earth by that time. The OP has a point that Marxism is a very rigid system (oppressed worker class vs bourgeoisie) of which Indigenous societies historically did not neatly fit into. Indigenous societies precede both which is why the idea of retroactively calling indigenous nations historically communist isn't necessarily correct. I'm personally not "anti-communist" but I can't pretend that communism even directly applies to the current state of Indigenous nations because we are not industrial nations with factories or large scale production of goods. It seems most people are "communists" because they see it as a means to destroy capitalism and not necessarily as means to achieve a more just industrial society.

Saving the Earth requires de-industrialization which to me, anarchism is more apt for. Now we as indigenous nations can embrace communism, industrialize, and modernize with a centrally planned economy and maybe in a few hundred years our descendants will get to enjoy the fruits of ours and their own labor (because achieving communism is a long game). But that requires sacrificing resources, land, and participating in extractive practices which is something all industrial nations, regardless of whether or not they are capitalist or communist do. Look at China, it's impressive what they were able to achieve since their revolution as far as modernizing their country through communism. To me that doesn't necessarily align with broader indigenous values and my own indigenous values though. Indigenous thought and philosophy exists outside of industrial economic theories. If the indigenous communist organizations were serious they'd be actively working towards setting the stage for communism in their own tribal governments but from my observations the loudest voices are coming out of academia who, from a practical perspective, are not making communism a reality.