We discover through Verin's notes that over 200 sisters are actually BA. This out of roughly 1000 sisters total, meaning that more than 20% of the Tower is devoted to the Shadow.

This is an extremely large number. I would venture a guess that no other grouping of people anywhere has such a large segment corrupted by the Shadow (with the possible exception of the Black Tower). Certainly, the impression we have from how people think of Darkfriends would indicate that DFs are few and far between everywhere in Randland.

The only other time I can think of where we know of a large group of DFs in one place is in TGH when the Shienaran DFs are gathered up by Fain and used as Trolloc fodder t/o the book. IIRC the group numbered less than 30. Surely this a far smaller fraction of the population than 20%.

So, are we just mistaken? Is the Shadow more prevalent in society than we think (is 2 out of every 10 people met a DF) or is the White Tower just that much more corrupted than anywhere else? If so, Why? If you suggest it is the power of the WT, then why aren't other organizations with power as fraught with DFs as the WT? Shouldn't 20% of Whitecloaks be DFs? Or 20% of Wise Ones? Or 20% of the nobility in Seanchen?

What makes the WT different?