Superman would take out a hundred or so, very quickly - read Red Son.
Flash might take out a hundred or so.
None of the other characters are fast enough to speedblitz like that - and speedblitzing is the only thing that'll work against the combined power of the GLs.
You get into a protracted fight and you're going to lose.
It's basically Supes and Flash vs every GL.
I think it'd take them a few seconds to take out every GL - and within the first coupla seconds, they would have all combined their power into a giant green shield.
Then it'd turn into a giant hammer and squash everyone flat lol.
The GL Corp would win.