... is that RJ said he had a strength list of all channelers multiple times. He discussed a strength distribution bell curve which clearly had non-Aes Sedai, since 37.5% of women in that curve aren't strong enough to be AS. Maria, at a later date, said this curve maps to the strength levels, another indication that people like Morghase would be on that level. Finally, Terez saw Moiraine's new strength listed on that list, and she was not even strong enough to be raised Accepted after her time with the Finns.

And if you look at the detail of the second entry, which is about Serafelle, its clear RJ mapped out his world in meticulous detail, not based on just what he needed to show.