Corran and Ganner win for sure. I know someone will probably call me a NJO fanboy, but listen to this, Ganner, the weaker of the two, was able to defeat at the minimum several hundred Vong in one fight. The only way they were able to stop him was by sending in heavy weapons. Seeing this, he brought down the ceiling of the building they were in and killed several hundred, perhaps several thousand, more. His actions were so revered by the Vong that he became known as the Guardian of the Underworld by the Vong. This is by a people who are almost as good, if not better fighters then the Echani. Impressive, I sure think so.
So, Ganner kills Kit, Corran kills Vos. NJO guys win hands down.
Fisto and Vos. Ganner was considered and average - below average Jedi by the others, so he'd be dispatched fairly easily by the older, more experienced, and more powerful Jedi Masters. Corran by now might be more than a match for either one of them of on their own, but even one of them would be able to hang with him long enough for the other's assistance. Against both of them, I don't see Corran walking away.
Now, if this were Ganner by the end of Traitor, the NJO Jedi would win, as Glentract said, hands down. But as it is, the newer guys are going down.