Disticnt row values of particular row in to other datatable

we could shorten to

dt1.AsEnumerable().Union(dt2.AsEnumerable()).CopyToDataTable

Handling empty results we do:
:ambulance: :sos: [FirstAid] Handling of The source contains no DataRows exception - News / Tutorials - UiPath Community Forum

But we do feel, that a different result is expected which we will not produce with the union