I think the same is true in the reverse. You can't assume that because you lost without Bach or Sears, and your RB that
you would have won. And you certainly can't assume with Zach gone, that the team you have this year is so much better than what BYU returns.
All the guys that ripped that defense except Zach and Milne are back. And Baylor Romney, the guy that ripped that defense in 2019 is back, and if he or Hall are a toss up, that's bad mojo for your guys. And then you just have to look at what is back Allgaier (one play says it all, but he had many plays), Katoa, is back and now we have Rapati, McChesney, etc. Gunner Romney, Pau'u, then add the Nacua brothers. Rex was an animal, now it's not just Rex, Holker is back, Wheat, and Wake, and the OL returns 4 guys who got lots of PT last year.
The key is which QB can run it, we've seen Baylor do it, we've seen Hall do it, and both can run this offense.
So, there's a lot you can draw conclusions about, without going overboard.
I worry that the DL will be good enough to stand up to the Boise OL, but not the LBs, there are literally 8 guys at LB who can do the 'plug and play' game. And for BYU, the DBs are probably the most experience group ever returning. So it really comes down to the DL.