Recursive element - mismatch column names between mapping classes

I run the E2eRecursiveXmlTextSourceTestScript; the XML view model from XSD contains mapping classes Employee and Supervisor. Next I copy the attributes from Employee to Supervisor. If the order of columns in Supervisor isn't the same as in Employee, I get
"Mismatch column name between mapping class Employee and Supervisor"

I am not sure if this is bug or if the message error is considered self-explanatory.