Chances of a virginia, armsy and group of pale cannibals spawning together on day 7?

This is my first playthrough of the forest, and I was playing with a friend who has experience, and he's never seen this before. Is this a rare occurence? We were on the headland and while the virginia and armsy left us alone, the pale cannibals did not. They all appeared at the same time, for reference. The armsy and virginia were walking together it was horrific