In a world that made a bit of sense, they could establish an advisory pool covering all areas of the country, either by treaty or ethnic 'tribe (there are a lot fewer 'ethnic groups than 'nations') plus Inuit (I'm purposely ignoring Metis) which could be drawn on depending on who is impacted by a particular project (i.e. Treaty 5 and Inuit for the Port of Churchill project). It would make logical sense, but would never work since they all claim to represent Turtle Island. We have created the problem by establishing a nation-to-nation relationship with individual communities, many of which have populations in the few hundreds. Canada didn't sign a treaty with Moose Factory or Poplar Hill FN, they signed Treaty 9 covering most of far-northern Ontario.
Many nations govern by consensus, so basically every single FN member claims a vote. If you've ever been to a FN council meeting, everybody gets a chance to talk. Whether anything is ever decided upon seems secondary to everybody being able to have a say.
Layer onto that the fact that some FN communities are divided between traditional (i.e. hereditary) and elected (i.e. 'white man's) leadership.
At the end of the day, in the vast majority of cases, money will talk. It's a bit of a shakedown.