Bingham is the top because they are the best program in the state year after year regardless of what region they are in or who is in it with them.
Herriman is a good program though, they should be tough.
We (American Fork) play Herriman this year so we will get to see first hand which of those two is the better team. Of course Herriman was in our region until last year, and we still played them anyway last year, so we're pretty familiar with them. I'm not sure who else Herriman plays from region 4 this year?