this is a really easy one. Kakuzu and Mei win easily. Konan's really only good when working with Pain, or when she's on the lake that she made out of paper bombs. and Tsunade's a close-range fighter, and a medic. Both Kakuzu and Mei are mid-long range fighters, so Tsunade won't even get close. And Mei's fire-based techs would burn through Konan's paper, meaning if they're not on the sea where she fought Tobi, Tsunade and Konan are screwed!