Charleston has too many country stations. But they are all cash-cows for their companies so that's why there are 3 instead of 2 stations like it used to be. Cumulus (previously Citadel, previously Wicks, previously Dudley) has basically had the same station since 1990-91 (107.5), while Apex makes a lot from 92.5.
Apex and Cumulus fear switching because their ratings points would go to the other two stations, and that would threaten 99.7 or Z93's reign at the top.