My take in this fight (I have not read the discussion)
Location: (We are inside a huge dome shaped cave) this makes it harder for Sakura and Chiyo to dodge Kakuzu mask's elemental attacks, do to the restriced suroundings, so already there Kakuzu will have an advantage.
Knowledge(intel): you say there are none, but really, are you telling me that Kakuzu, "the bounty hunter" won't have any intel, what so ever on such an old and famous shinobi as Chiyo? (even Chiyo herself brags about the fact that she was known for capturing a castle alone with 10 puppets) So it's pretty logical to expect that Kakuzu will know that Chiyo is a very skilled Puppetere, and by knowing that he should also know that almost all puppeters use poison on their weapons and puppets.
So here again, I will give Kakuzu the advantage. (lets just disregard Sakura here, she would not know anything about Kakuzu, nor about her teammate actually... another minus for them)
Restrictions: None, and here im just thinking, if Kakuzu can use his fire mask and his wind mask at the same time to make a combined attack with those 2 natures what is standing in his way to mix up other elements? sure we have not seen him do others than the fire/wind combo, but are you really telling me that a Shinobi as old and as experience as Kakuzu, one that can use all 5 elements to such a extream as he can, have only managed to combine 2 elements? And yes I know it was never shown in the Manga or the Anime that he could use others, but I would still expect he could use more than just fire/wind.
Distance: The distance is far enough for Kakuzu to be able to releace 4 of his mask, and even if Chiyo and Sakura start a frontal assault to close to gab betwean them instantly, all Kakuzu needs to do is jump backwards, and he would have gained himself all the time in the world for his for masks to be released (wind, fire, water and the lightning mask) and then begin his elemental bombartment.
Age/Experience: Sakura havn't really been around for to long to be that experience, though she is pretty clever, so she should be pretty quick to analyse Kakuzu's moves and attack's, if she survives that long. Sakura might be able to dish out super human damage, but how well does she tank it herself? A Doton Dumu hardened fist or Kick will easily break bones. And Sakura will need at least one hand to be able to use her Medical Ninjutsu, if Kakuzu managed to break both her hands, or simply rip them off, she is done for.
Chiyo is very old, not as old as Kakuzu (who is 96) but she is deffenetly past her prime, even though she have replace one of her arms with a puppet arm, that won't change the fact that she won't be as strong as she used to be.
Kakuzu have never been as strong as he is now, do to the fact that he have replace his intire body, mussels, organs, ecetera with threads. (he only have his eyes, his skin and his 5 hearts left) So just like Sasori, the only way to kill him Is to destroy his heart, and he have 5 of those...
Which means that Kakuzu is Immune to Poisen. (as long as a poisoned blade don't penetrade any of his 5 hearts) So a random cut on his arm, chest (or whatever) won't do anything to him, which mean that he won't be forced to use his Doton Domu to tank the poison coated weapons but can go on the offensive if he so desires.
And the fact that Kakuzu could play dead and attack them when their guard is down is a huge, huge advantage for Kakuzu, heck he might even be able to Take out Sakura this way, if she have even managed to survive that long...
some feats Kakuzu have done:
Kakuzu Bit** slapped Asuma with a brief case.
Broke down a gigantic iron gate with a single punc.
Outmatched Kakashi in taijutzu.
Out smarted kakashi with a water clone.
Blitzed kakashi when Kakshi had taken down the first of his heart (and had it not been for plot no jitsu involved Kakuzu could have punched him in the back of his head with a Domu hardened fist, which would have taken his head clean off!)
Kakuzu tanked Choiji's Human Boulder attack, if he can do that, he can also tank Sakuras punch, and he you might be thinking that I am just grasping after straws, but I really don't think I am.
People just don't grasp how good of a defensive tecnique Kakuzu's earth spear actually is (It is as though as diamond! and the only think that can destroy a diamond is another diamond, or an extream high tempature)
To be able to penetrade Kakuzu's earth spear you will have to have a high level lightning ability (as states in the manga) which neither Chiyo or Sakura have or a weapon made out of diamond (which neither of them have) the tecnique pretty much makes Kakuzu invinciable, so Kakuzu could just Domu up and stand there doing nothing, while his 4 masks are runnung around, and Chiyo and Sakura would have no way to counter his Jutzu.
and with those feats how would Chiyo and her puppets, led alone Sakura even stand a chance against him?
Oh wait, she couldn't.
