Hrm who's the best choice for them to blindside? Whether this is the last tribal before a merge is very important too.
I'm not sure Sue is the smart choice if they still have another tribal to go. She's 'family' and her departure leaves only good(ish) players of the alliance remaining so it'd still be Conner, Craig, Kate vs Phoebe, Kristie. Whereas if they get out Conner they eliminate a bigger threat when it comes to the individual game and don't piss off the alliance as much because he's not an original original.
Plus if they do have another tribal Phoebe and Kristie might be able to convince Craig or Kate to go for Sue because she's a weak player like they did when they got them to vote Andy giving Phoebe another week.