In other words, why go to all the trouble of creating a mechanism whereby a transmigrated Forsaken's strength can be reduced, if it is to have no real impact?

Where Semirhage's source of strength was her reputation as a torturer, and the fear this evoked in others, Lanfear's source of strength has always simply been her STRENGTH. The fact that it is superior to that of the other Forsaken females.

So, if RJ was somehow attempting to strip the Forsaken of their auras of greatness, would it not make much more sense to reduce Cyndane to the unfamiliar position of being weaker than some of her competitors among the Chosen?

I think it would fit the pattern.

But, as we've already said, we cannot be sure. After Sanderson's first, incorrect quote, we could place Cyndane below Nynaeve for sure.

After his partial retraction, we don't know how far we should move her up again. He still maintains she is significantly weakened. And his emphasis on the 6 women above Nynaeve did not tie up with his uncertainty regarding Cyndane. Basically, it does not seem as if she was one of the names among the 6, else he would surely not have made such an issue about her reduced status.

Anyway, until Sanderson clarifies what he meant, the debate can continue.