There are a myriad of things I would want us to take into consideration here before we jump into it.
First of all, Oro knows about his Susanoo arrow speed, his Amaterasu and his genjutsu, since he got all of Kabuto's info. Jiraiya also has some knowledge of Amaterasu so he'll know not to let any of that get on him.
Sasuke favors Susanoo more than any other Mangekyo technique. He prefers it most times to Amaterasu and Tsukuyomi.
Orochimaru's Rashomon gates do not require hand seals.
Orochimaru knows about the existence of Manda 2 and should be able to summon it.
Tsunade has Susanoo shattering strength and healing prowess.
Jiraiya has Swamp of the Underworld which, according to the Databook, is employed in restraining large summons. So basically, it has enough strength to hold something as strong as Gamabunta or Manda.
Both Oro and Jiraiya have been stated to have Sage Mode.
The Sannin fight mostly at long range.
Oro has the ability to go underground. Oro's Kusanagi is powerful enough to push back something as powerful as Four Tailed Naruto over a distance of many meters.
Now the battle.
Sasuke's normal fire release is matched by Jiraiya's and Oro has wind to supplement Jiraiya's to make it stronger
As for Amaterasu, Oro also has knowledge on it and can summon snakes to surround Tsunade and Jiraiya and thus give them some degree of protection. Gaara did something similar with sand for Kankuro and Temari when he fought Sasuke at the Summit. Tsunade can do something similar with Katsuyu clones. Also, Jiraiya can hide in the shadow of a snake or slug the way he hid in the shadow of one Ame ninja. He can have a clone write up the sealing formula for the Fire Sealing Method while he fights.
As for Kirin, Tsunade can have them all enter the 1/15 of Katsuyu, whose protection could withstand Pain's village buster.
Finally, Susanoo. Sasuke's Susanoo arrows, shuriken and other projectiles will be countered by Oro's Rashomon gates which require no seals and can stop a TBB. They can then counter with Jiraiya's Swamp of the Underworld which would bury Susanoo. Considering Susanoo is a being of immense strength, let us assume it can at least struggle against the Swamp's hold. The databook said 'the more you struggle the more you sink' so he's making things worse for himself. This just leaves an opening for Oro to push it deeper in the Swamp with his Kusanagi, and the databook said the swamp is almost bottomless. Tsunade can also punch it deeper into the swamp with her monstrous strength. He will sink and and suffocate in its dark, miry depths. If Sasuke tries to deactivate Susanoo, remember he is at the head of the Susanoo, so he won't sink at first and will have to opportunity to do this, That would leave him open, in mid air for any number of attacks; like a Kusanagi launching, a Jiraiya hair attack(which could rip a crab to shreds) Katsuyu's acid or maybe a good ol' Oro swallowing for body swapping later.
If Sasuke tries to use snakes, remember Manda II is bigger than old Manda and so can swallow Sasuke's Aoda. Jiraiya can make a Swamp for the snake as well, Oro can tear it apart with his Kusanagi. Also, Manda 2 can shed its skin like Manda and thus survive Amaterasu. It can also travel underground to where arrow attacks cannot hit it.
The Three Sannin are far too resourceful to lose here.