"Suppose I have a structure A with a, b, c, d tables inside. My aim is to use names of tables within structure A (a, b, c, d) to create new tables in structure B."
So, why does this not work?
New structure B will have all the same fields (a, b, c, and d) as existing structure A with the same names. Each field in the structure will have the same table as in A, which is what it seemed like you were trying to do when you assigned the tables. This also means that all the columns names of the tables of structure B will match the column names from the tables of structure A.