I've played some multi-team games, so the theory is actually the same.
The addition of a vengeball is getting you people to off topic.
Okay, let's say there is a blue mafia and a red mafia member.
They both read each other as scum, and since they know their teammate, they know that person is on the other mafia team.
When I played as scum in a two mafia game, in which we had daytalk (a standard rule), we strategized that we would pick off townies.
Because with 5 vs 4, including the vengeball, the townies would be the most dangerous players.
I guarantee you that mafia are not hunting each other. They are hunting townies.
Right now, it is 5 vs 4. As it should be. Regardless of color or affiliation, there are 4 scum.
They're thinking the same thing. There are 5 townies.
Once we are eliminated, the mafia would then proceed to fight each other.
That is overall the best way to win as scum, and the best way to fight as town.
If the game is played with 5 townies, two red mafia, and two blue mafia, then town will win EVERY time.
Unless......... scum act as one team until town is out of the picture.
I've seen this play out, and all the theories of what scum would do have sounded quite unrealistic so far.
Whomever said "scum would hunt each other" has an FOS. I'll have to look back.
The above comment is something scum would say.
If they discover each other, then they will cooperate to take us out, and fight 2 vs 2 later on in the game.
Town loses if scum read each other. I'm going to make a hell of a suggestion:
Letting scum know their future enemy, and current ally, is the WORST possible thing we can do.