the idea of having VV3 visit vv2 and vv1 island is not to discover the old tribes but to gain the ability to expand and explore other sorces of food and new puzzels. You can only keep poeple in one place for so long before we get smart and learn to explore. The more villagers you have the more room your gonna need, so enough the villagers will learn how to make a boat. you`ll see in Virtual Villagers XXIII. LOL