I was comparing BYU WR/TE to Utah WR/TE when I gave the edge to BYU.
It might make more sense to compare BYU receiving options to Utah pass defense, but it's frankly a more difficult comparison, which is why I was just looking at position groups. Right now, BYU probably has a stronger or more proven receiving corps. I'd neglected to include Dixon, but even Covey, Kuithe, Dixon vs Pau'u, Romney, Rex, edge probably goes to BYU. Not a massive edge, but something, especially (as you point out) with the uncertainty and loss of Holliday.
Agree that Utah is almost certain to find/develop a strong RB though, which (along with the defense) is why I think Utah has to be favored. But plenty of favored teams lose games, and the most important position on the field is still a relative question mark for both teams.