Need a Question during Merging of NameMapping if it want to create a duplicate object

It would be helpful if we get a Question during Merging of two NameMapping files if it want to create a duplicate object or overwrite exisitng object.

If the object is already exisitng is both the Namemappings.

Presently it just creates a duplciate object with "Objectname_new" .It would be helpful if it asks us to overwrite or create a duplciate object.