Concern over which children are fathered by which brother falls on the wife alone.
She may or may not say who the father is because she does not wish to create conflict in the family or is unsure who the biological father is.
Historically the social system compelled marriage within a social class.
When the People's Republic of China annexed Tibet, political systems in many regions of Tibet remained unchanged until, between 19, political reforms changed the land ownership and taxation systems.
The eldest brother is the head of the family, and is privileged to be called “daddy” by any resulting offspring.
In New York and New Jersey, they live primarily in Queens and New Brunswick.Most children won’t know which of their ‘uncles’ is actually their biological parent, but it doesn’t seem to matter.