I've thought of an idea!!
"Villager Tranfer" could be an option in VV3.
If someone starts off with a couple of tribes in different games, then the player can swap certain villagers to solve certain puzzles.
i.e: Swapping Master Builders to solve a certain puzzle in VV2 LOL!!
ALternatively, Villager Swapping can be ideal for players who like "Selective Breeding".
Don't laugh at me.... I'm only abit frustrated with my Master Builders that's all

But It COULD be an idea!