That's not too important. If I go to my closet and pull out twenty items of clothing at random, and designate those group A, and designate the rest group B, if I know what is in each group I can still make predictions about traits of random members of either group.
This thread is for discussing anything that doesn't seem to deserve its own post.
If the resulting discussion becomes impractical to continue here, it means the topic is a promising candidate for its own thread.