Neither does Islam ---the nuclear family isn't 4 wives and as many concubines and sex slaves as you can afford to buy. Bin Laden was one of 52 children and his mother was a concubine ----that's not what we call a nuclear family.
In fact, for Israel's sake it's a good THING that Jacob did.
An extended family ordinarily refers to one which brings/keeps cousins within the meaning of family.
My mom and dad constituted a nuclear family. My mother's 9 sisters and a brother, their spouses, my cousins, my cousins kids, and everybody else up to nearly 200 people constituted an extended family.
My father's experience with an extended family ended with his father's generation. But they used to live up on top of Weed Patch Hill in Brown County. It was village of cousins, and much of the property was held in common (or communally). There were more than 200 people involved in that one so it was more of a tribal situation.
Actually it was a tribe, but I'm not clear on which one(s). The Bin Laden family was just a hum-drum, run of the mill polygamous, but otherwise nuclear, family, much like hundreds of millions around the world!