UCF and Cincy have advantages that BYU doesn't ( and vice versa) so I can see ranking them (especially UCF) ahead. But Boise has zero reason to be ahead of BYU.
My personal ranks for top 5 expansion candidates (Big 12 edition) go
1. UCF
2. Cincy
3. BYU
4. Houston
5. Memphis
If we're focusing on PAC12 expansion, it's
1. BYU
2. UNLV
3. Colorado St
4. San Diego St
5. Boise St