Kakuzu and Hidan, Pre-War or Not.
You have a seasoned Shinobi whose been surviving on his own for over 60 years in the Ninja World and who is a seasoned Bounty Hunter, paired off with a Foul Mouthed Immortal who excels at Taijutsu and Voodoo against a drunk who is called "The Legendary Sucker" and girl who couldn't kill a blind, chakra drained opponent (Sakuske).
Now, in all fairness the Sakura and Tsunade are good at punching and healing. So between the 2 of them, they could probably take Hidan out.....though not before he cuts one of them. This wouldn't be much of a problem, if Kakuzu wouldn't be nuking them both from a distance. Knowing Sakura, she'll most likely get injured and Tsunade will have to play medic and defensive against Hidan and Kakuzu (the latter of which, doesn't care if his partner gets caught in the cross fire). That won't end well for either of them.....