The Y-107 model was a nice idea, as the stations had the convenience of a common frequency, but even with synchronization, they had to treat the stations as though they were distinct entities; they were not permitted to overlap, which left a lot of people out.
Thunder 106 broadcasts WKMK on 106.3, with the WTHJ simulcast on 106.5. Those stations DO have overlapping coverage (although as first-adjacents, I thought that wasn't permitted).
But unless a company insists that the number be part of the station nickname, it is not necessary for a simulcast to use the exact same frequency. "The Breeze" is on 107.1 and 99.7, so if Press wanted to reach farther north, that decision isn't contingent on being able to buy only WFAF.