Captains ftw. They have the most versatility, better stats than Akatsuki (not so much the admirals) and the most numbers.
You forget that genjutsu and kekkei genkai are at play and the akatsuki they don't kill there own teammates as they work as a real team Nagato,Obito,Itachi and kakuzu would really be on higher levels then the Gotei
Admirals here would easy be on bleach level
LOL you know what i just realized. Everybody would probably shy away from the admirals because of how freaking tall they are. Anybody notice how in one piece high tiers just get this super growth spurt?
Anyway that aside. Knowing the akatsuki they will probably try and attack the people with the least numbers. Kizaru will then proceed to one shot sasori and deidera without them even seeing. They will think twice.
The only problem on the akatsuki side is that dude who can't die. But yama's shikai can turn him to ashe in one shot and he has never shown any recovery from that level of destruction.
I say the captains take it though. Depending on how they dispatch the akatsuki they probably wouldn't be able to just go right into another battle against the gotei 13 considering by this time yama would have already decided all of them are potentia threats and goes bankai which will immediately leave all of them out of the game. However does heat affect light beams? Because kizaru could fire them from afar to pierce yama's heart and body but that still hasn't even included the other 12.
Not to mention aizen reveal to all of them he has fathered them all providing mental trauma for the rest of their short lives.
Captains take it with quite a few losses though. Because aokiji can just instant freeze the entire akatsuki. Itachi could probably defend against it with his susano'o but that'll only save himself and he can't keep up the susano'o forever and i doub't he could put it up in time to survive it. Then it'll be the admirals vs the captains and after yama sees just how dangerous they are he is going bankai no questions asked.
Gotei win. Yama can take out those who cant handle his heat. Mayuri has his poison. Aizen is there. (>_>) Soi Fon just needs two hits. Komamura is immortal. (>_>) We haven't even seen Shunsui and Ukitakes bankai. Byakuya. Unohana. (>_>) Kenpachi. (>_>)
Too many powerhouses and hax users on the captains side. They could essentially stomp. Akainu and Aokiji are non-factors due to Yama. Oro, Kizaru, and probably Pein give the most trouble. Everyone else can be beat by shunpo, kido, and bankai.
Admirals are most certainly not winning this. The conditions are the least favorable for them. Gotei 13 seems to be start of series, so they have Aizen, Gin, and Tousen (with Aizen and Tousen having only his Shinigami abilities). Only person in the Akatsuki notable enough to take on Admiral or top tier captain fighters in their final form is Pain.
The White Zetsu Army >>>>> Gotei 13 fodders. In fact, the only captains in the Gotei 13 that can take on a hundred thousand Jounin-level Zetsus would be Aizen, Gin, Unohana, Kenpachi, Yamamoto, and possibly Komamura. The Zetsus however will be murked on by the Admirals.
Blahblahblah considering how the only legit threat in the Akatsuki is Pain against a handful of captains who can stomp him, and Admirals losing their intangibility.....
Gotei 13 wins
Ok. But don't you think Yamamoto's, Gin's and Komamura's final bankai would be very hard to deal with? Gin's attack is a 1 hit kill and nobody except arguably the top 3 Akatsuki could react to it. Or what about Hougyoku Aizen and full potential Zaraki? I think there are too many heavy hitters on team Bleach not to mention they have the best mobility and versatility character for character.