Utah are going after the same guys. If you look at the number of head-to-head battles this is undoubtedly true (especially if you look at guys who both schools are going after hard, not just guys who BYU or Utah gave an offer to and then cooled on). If Utah is doing well in the P12 they get a lot more attention in the country, especially in the west, and its recruiting classes fill up with a lot more non-LDS kids from outside of Utah. If Utah is struggling, it seems like it's much more likely to push harder for local kids and LDS kids who would otherwise be going to BYU. A successful Utah certainly hurts BYU occasionally, but overall I think there's a reasonable argument that a successful Utah helps BYU's recruiting. I think the same is also true for USU; look at how much better USU has gotten since Utah's recruiting has ticked up, USU is now getting a lot of guys who would have gone to a MWC Utah.