You can look into a mapping approach, as described e.g. here
You would need to create a table with two columns, first column showing all possible ways to name an employee, second column the employee's official name or id, like you want it shown consistently in the data model.
You can then load this table as mapping table:
Then when loading your tables, use ApplyMap():
ApplyMap('MAP', Description1, 'No Mapping found') as NewDescription1,