The benefit is Bonneville paid them more for the rights. And as for 620, they just took the last of the local coverage away from the competition. All they have to do now is steal away Jurecki and 910 will be completely worthless.
I know why Bonneville did it. But from the Coyotes side, who's giving them the most money shouldn't be the primary factor. I believe that splitting over three stations with the majority on a small gospel station is detrimental to what they are trying to do.
That being said, things like coaches shows etc on 620, which is by far the leading sports station in the market, could help offset that significantly.