Now, Utah has the streak and USU is competive. Add in the Boise State game that favors BSU and another 4 or 5 P5 opponents.
You can list off Liberty, UMass, and FCS all you want, but BYU has like may be 4 or 5 record-padding games per year...instead of the 8 provided with the WAC and MWC schedules.
It's the same formula that Boise State is using to grab nice-and-shiny win-loss records and land high rankings. Even lose to unranked BYU and still land in the top-20. BYU would lose to unranked P5 teams like Boston College and UCLA...but still finish with 10+ wins and a conference championship...that led to rankings.