In 2017 fans said the same thing... Utah actually lost 4/5 starters to the NFL. I don't think anyone on that roster doubts the OL. I don't know what else to tell you. Look at the stats BYU gave up 29 Sacks compared to Utah's 32  (with a tougher schedule). Utah returns about 5 less starts. I think both teams have two potential NFL guys Christensen & Hoge, Ford & Paulo. Utah has a coach that has had six guys drafted in four drafts. He's a proven coach. It's OK to think your rival will have good position groups. 

Byu has some elite TEs, Byu has a great DT, two great OL, a nice S or DB in Ghawaluku. However, boths schools OL won't be lower than the 40s in advance stats.