Besides, what's the point of filling in everyone's SimBio, "This is So-and-So. He is mean, and likes to scowl. Do not feed him."
The point is that you can make one sim who is not mean and does not like to scowl, and everyone else will make his life miserable for dramatic effect.
This business about the number of families: is this a game issue or a personal preference? Is it the number of families or the number of sims that causes the game to explode? I can see how having a large number of families would make gameplay rather slow if one was keeping them all in synch, but does it have any negative effect on the game's internal operation?