I am wondering why is there no simple mapping?

If i have 2 content types one called contentA, other contentB import doesnt work until i change the name of the both to contentA. Ok so i can change content type name to be the same, drupal allows this. But then you come to field name, and drupal doesn't allow it so I have different names in source and destination and then I have to manually replace names in export code, and IT WORKS like that. Even for images. Why not add some simple functionality for that in UI?