well if it was right off the bat. with out batman knowing anything about them he would lose. as for green lantern sasuke can put him in a genjutsu then take his ring off and Naruto can just speed blitz him. so I think they do have a chance against them and would help the league out a lot.
They could help the league sure, but as far as Sasuke taking the ring, the ring works off of will power and Sasuke does not have strong willpower as evidenced by his flip flopping emotions. Even under genjutsu any one of the Lanterns has a stronger willpower than Sasuke, Naruto could give them a challenge in willpower though.
I really don't see them being able to beat let alone touch he Flash, he's faster than Naruto and can go intangible, they couldn't touch him. He can run around the Earth and amplify his punching power that if he hit them would shatter bones.
Aquaman's water hand allows him to dehydrate an enemies body killing them instantly as well as gives him regenerative properties meaning any physical damage would be healed and how would he be weak against Sasuke? His trident is unbreakable so Susano'o couldn't even take it out as strong as Susano'o is.
Martian Manhunter is way too much for them, he's close to the strength of Superman and can also phase his body to avoid physical damage.
If they fight as a team they could fight most of them but 1v1 I think they'd only beat Wonder Woman, Hawkman, maybe Batman on a first encounter, Cyborg, maybe Green Arrow(the comic version has plenty of nifty trick arrows, could sleeping gas them)