BYU deserved their seeding and ranking. And I'm not sure BYU would legitimately be a 3 goal underdog to UNC. Maybe, but UNC is not Stanford level this year, and they didn't look convincing at all against Washington State.
UNC should have lost about 2-0 to Stanford. But the UNC program as we all know is clearly the most dominant by nearly an order of magnitude, at least historically. The past 4 or so years they've gotten competition but their roster is still a who's who of national-caliber stars like Stanford's is now.