I am afraid that my limited knowledge doesn't allow me to come up with a solution.
Using families is something I am not familiar with, I don't even know how you manage to count the individual members (enemies) within the family. On my tests it just returned the value 1, which was referring to the family, not the objects. This is relevant to your inquiry about selecting the enemies 1 by 1.
Again, a brute, hard-coded system (that will create the enemies 1 by 1, set their position and attach a linked life-bar), is as far as I can get. As I understand, you want a dynamic system (perhaps based on arrays), I hope that some other forum member, with greater experience/skill than me could provide you an answer...!