Two village one mafia is dead. Or should be.
As you probably know, Inventions Mafia has recently ended. It had a large number of problems, including inactive players, imbalanced teams, and too much of a "timezone factor" in determining lynches. The two-village-one-mafia format has several problems with it that make it worse than the one-village-two-mafia and multi-team formats, including becoming one-sided early, reducing player involvement, making idling more of a problem, creating kingmaker positions, and making timezones and stealth lynches more important.
First, whichever team in a two-village game wins the Day 1 lynch immediately gains the upper hand and can destroy the other team. Once one village is reduced in numbers, that village becomes powerless in the lynch barring a mislynch or mafia assistance. The team that wins the Day 1 lynch will become further and further ahead.
To balance this out, the mafia and wolf have to support the team that lost the lynch. However, most leaders of the losing village would be reluctant to share any information with the mafia, and the mafia would not want to share its information either in case the losing village started winning again. Also, the losing village could reveal the mafia to the winning village, causing the winning village to lynch off the mafia rather than the losing village. Also, the mafia's votes are usually enough to swing the lynch from one village to the other. Whichever team the majority of the mafia and neutrals vote with on Day 1 will probably end up winning, putting the mafia and neutrals in a kingmaker position.
Since the lynches in two-village games are usually very close, timezones are much more important than in one-village games. The team with more players who are awake during the day is the team most likely to win the Day 1 lynch, effectively making the game decided by timezones. Stealth votes cast by the mafia to swing the vote from one team to the other are also more of a problem in two-village games because there are so many more opprotunities for them to happen.
In two-village-one-mafia games, fewer players are heavily involved in the game, and the consequences of idling are worse. In a normal one-village game, all eight mafia members, the village leader, the backup village leader, and any neutrals will all be actively involved in the game, i.e. not just taking orders. In a two-village game, one mafia faction is replaced by a village leader and a backup leader, reducing the number of involved, strategizing players by two. The consequences of an idling player are also worse. In a one-village game, idling mafia members can have their night PMs sent in by teammates, but since there are fewer mafia members in two-village games, there are fewer opprotunities to fix idling problems like that. Also, villages need every player in lynches, and even a few idlers can ruin a team on Day 1.
In conclusion, do not make any more two-village-one-mafia games. The format has been tested and is not as good as the one-village-two-mafia or multi-faction formats. There are multiple flaws that make two-village games less balanced and less interesting to play.