This ultimately depends on one's definition of "greatness." To me, the measure of greatness AT THE HIGH SCHOOL LEVEL is sustained excellence over a long period of time; i.e., through multiple cycles of kids.
Irmo obviously has a great program, regardless of the trophy count. So does Wando, which hadn't won a state championship for many years before last season's breakthrough.
The reality is, whoever GETS TO the Class AAAA title this year will likely have to get through Irmo and Wando.
That I can say the same thing in most years is a much better measurement of greatness than the outcome of a single game.