If there are 5 persons born, 1957, 1959, 1979, and 2 x 1983. is it good to stay together?

Thomas,
Assuming that none of them were born at the beginning of January, to these respective years you’ve mentioned, and the first person is a Fire Rooster, then the second person is an Earth Pig, and the third person is an Earth Goat, and the last two people are Water Dog, I would say it is not possible because of the following reasons. The people born in the year of the Dog will find impossible to get along with the person born in the year of the Goat. This togetherness you asked about, I think is not possible from an astrological point of view. It will end in a split of this group of people.