Someone "adopted" into a different tribe (there was no legal adoption in biblical times) remained a member of the tribe in which they were born. Someone from the tribe of Judah did not gain the ability to serve as a priest simply because he was adopted into a Levite family.
Members of the different tribes could marry whomever they wished. There was no restriction on someone from Judah marrying someone from Benjamin. The children would be considered as being of the same tribe as the father. The only restriction was with the Levites, who were expected to marry within the tribe.
Fine. Then explain to me what tribe a Jew belongs to that has no human father.
What tribe was Jesus born into?
SD