Assuming this is Orochimaru with access to all of his jutsu, then I'm absolutely voting Oro. He evenly matched 4 tails Naruto without the use of any of his non-summoning-related jutsu--he should be capable of a lot more with all of his techniques. While Sakura might have been able to single-handedly take down a Version 2 ANBU captain, there's no doubt Orochimaru would be able to accomplish the same, especially post-Fourth Shinobi War.
Katsuyu is meaningless here. Aoda is Manda's equal, and Orochimaru should be able to summon Manda II, who's much larger and stronger than the first Manda (as well as having arms/legs).
There's nothing Sakura can do that will put Orochimaru down permanently here. She never uses any jutsu, she just goes in with her fists--and against Orochimaru, that's just not enough.
...Also, bump.