coach at an FCS school to a position coach at an FBS school is not a leap at all. In fact, it seems like a bit of a steal in my opinion.
Where do you want BYU and Utah to get position coaches from? Successful position coaches at other schools will soon become coordinators. Unsuccessful position coaches will soon get the boot. Utah and BYU aren't going to be poaching position coaches from Florida, Texas, and Alabama. Successful coaches from the FCS ranks seems like the best place to get them.