since teams are random, cheaters would often not even end up on the same team. When they are on the same team, they would get an advantage, but with 12 players, 2 cheaters means, from the cheater's POV, there is only a 1/11 chance they get matched to their fellow cheater, and a 2/11 chance that they are opposing their fellow cheater.
so for 9% of the games, the cheaters would get an advantage, and when they are against each other, they would have the ability to strategically throw games in favor of whichever cheater had a higher score, so that it's more likely one cheater wins the tourney.
This seems like it would be sufficient to discourage most cheating and contain the amount of damage that cheaters could do to the tournament.
If there were more than 2 cheaters working together, the advantage would be larger. But that also means a bigger number of people who could rat on you later.