They have 900 students.... the bottom of 5A takes over 1500. If they add 600 students in 1-2 years... that's crazy enrollment spikes, holy cow.
They are a far cry from 5A. It's not a knock on SC to say that.
I would say a schedule of Jeff, Floyd, BC, Salem, CT, and NH would generally prepare you for the tournament, as well as, any other conglomerate of teams you could come up with.