Design Pattern question: how to "merge" Entities and Models?

AdminModel contains fields from commonFields in the table?
I didn’t quite understand the question, maybe it’s worth looking towards afterFind () to set values.
Your version looks to be working.

Yes, the tables for Admin and AdminGroup contains the same fields for historical reasons. Now with additional requirements we would like to make it possible to "OR" the fields from Admin with zero or more AdminGroup(s).