Actually, he attached himself to Cadsuane because of a viewing Min had that Cadsuane will teach him and the other Ash'aman a lesson they must learn. Some have theorized that it is the flaw of Callandor, but I think it is something more. She is the epitome of Aes Sedai arrogance. She is an extreme traditionalist, but has allowed rules to be broken (many she breaks herself) in order to get what she wants. She keeps everone off balance to maintain control. It is an effective tactic, but that doesn't mean she is not a B!tch. What she is doing is no different than the way Moiraine acted before she wised up. Even insane Lews Therin has more knowledge and wisdom than any current Aes Sedai (he was almost 600 years old at the breaking, if I remember correctly). The Aes Sedai were fragmented long before the official tower split, and the actions of Moiraine, Verin, Cadsuane (not to mention the rampant infestation of Black sisters), shows how uncohesive they really are. They have certainly forgotten that Aes Sedai means "Servant of All", not "Master of all".