Lunardi and Bracketmatrix.com do not determine who dances on Sunday.
Now that Joey Brackets does this pretty much as a full-time job, he has actually gotten pretty good at it the last 4-5 years. Last year he actually missed 2 teams, which was a off year for him---in '14 and '12 he only missed 1, and in 2013 he nailed 68 out of 68:
https://www.sportsinsights.com/blog/how-accurate-are-joe-lunardis-bracketology-predictions/
But it's nice to check the consensus as it's such a big sample size of the other experts like Jerry Palm, Patrick Stevens, etc (86 brackets). In this case everyone is in agreement, which is what makes it nice and simple this year.
www.bracketmatrix.com