Sheny wanted to bring Bail along with us, I think.
Also, if Mel found something (and if she did, I'm not sure why Bront didn't post it yet?) about Arden that is damning evidence, Rayni might be able to convince Sheny that the current plan really isn't a great one--Rayni thinks that trying to observe this guy is foolish because it gives up our advantage of anonymity and what do we have to gain? Rayni is generally all for charisma-based skills, but for a completely evil Telepathic Mind-Controlling evil quori spirit thingy that has more resources than you, you have to surprise them by striking first :\