Well, as in any community, there can be some differing viewpoints obviously, and any human community has differing views. The voices get unified together in some ways through the Sami parliament. Insofar as it's drawn into commenting on particular issues, there's a unified voice.
I'll add that there is more linguistic, more cultural cohesion amongst the Sami people than amongst the very diverse indigenous peoples of Canada. You do potentially get more of a unified voice there, but even then, you have divisions within any human community.