Jedi vs Sith
A Jedi team comprised of RotS incarnations of Anakin Skywalker, Obi-Wan Kenobi, and Mace Windu are sent as representatives of the Jedi Council, seeking a diplomatic solution to a Separatist movement on a random planet filled with hairy goulash looking aliens.
The Sith have orchestrated the entire movement to draw out the Jedi and strike them down. The Jedi are ambushed in the main auditorium by Count Dooku, Ventress, and a perfect clone of Darth Maul who was resurrected just to balance out this fight and because Ray Park demanded royalties.
For simplicity's sake, it's assumed that the fight is broken up like this:
Dooku fights Mace
Obi-wan fights Maul
Anakin fights Ventress
The assumption made is that the Jedi are surprised by the presence of the Sith and are attacked unwittingly, thus being immediately on the defensive. Since the fighters are fairly within each other's range when it comes to power, it's expected that no exchanges will be over immediately, and that tag-teaming will be impossible until the weakest link is destroyed.
Debaters are free to assume that once the weakest link has been destroyed, that the extra combatant may assist the weakest person on their team to balance things out. How this is determined depends heavily on your explained reasons.
Also for the sake of simplicity, we will not assume any offensive powers a la Push, Choke, Lightning, etc. will be used, but all combat will be saber-to-saber based, with H2H being a factor only if the combatant has a history of it.
If you simply say "Sith wins", or "Jedi wins", I expect reasons demonstrated for your case.