Not idle as they believed what they said, but apparently they were quite short of finding all. At least RJ has removed a good percentage of women they would miss for lack of any systematic testing. They get all sparkers. ALL. They train any woman who become an WO apprentice and can learn, not matter age or strength. They do not test any woman who didn't approach them or wasn't approached by them to be a WO apprentice. They just think they have a "nose" for finding learners, but really they don't.
Is this from the notes too? Because what Terez said seems ever so slightly different.
Nevertheless, I do think those who aren't found, or abstain, or do not become Wise Ones for any other reason, would be randomly spread through the bell curve. The Wise Ones don't reject the very weak, and I doubt they pressure the very strong into joining.