Ability to retain the selected order of import attribute mapping row in the data locator field

Current behaviour:
When we have a (automated) export from a system containing the Asset objects, we don’t want to have to manually manipulate the file based on some attribute mappings to concatenate them in to a text field.

Let’s say we have a CSV file with:
Firstname | LastName | Email

If we wish to do Firstname | Lastname | Username, we have to manipulate the input file.

Suggested solution:
As we are able to manually select which fields need to be concatenated, it would make a lot more sense to respect the order in which they are selected during the mapping creating and not the order in which the columns appear in the source file.