"I was just helping plan, I don't think I would be especially helpful, especially if you still have a Magic Circle Against Evil to spare."

"So that would be 4 with Ser Seelah and Lann... 5 if we also take the mongrelwoman or one of the cultists to help guide us."

"I know around where the entrance is, but not further than that."

They could just not bother with a Death Ward for Wenduag, she will probably run away anyway.

"I have detect evil myself, but I suppose someone else on alert with it is worth it on the margin.  Do you have any preferences on this Darth Occlus?  I don't know your full abilities, so if, for example, they render Detect Evil entirely superfluous we should leave Ser Seelah behind.  Or if you have abilities to navigate a maze we can leave the mongrelwoman behind." 

"I expect my native senses to be superior to Detect Evil in general, but particularly so in the environment we face, a series of small spaces with walls that may be too thick for it to operate. Taking a guide would speed our progress enough that I expect that to be worthwhile. I trust the Neather for this purpose over the cultists, and I trust the cultists over the Neather to not provoke the Prelate into executing them prematurely."