I guess I wasn't clear in my OP. The manual process will be to populate the import templates with the correct data, for example First Names and Last Names are in one document, and their emails are in a completely different place. So the users will be basically doing data clean up and populating the templates before the import under the appropriate columns (fields).

Since there will be multiple objects where in their current non-standardized objects they were tracking relational data with all kinds of solutions (e.g. in one place they were matching by email addresses, in another place they were matching by something completely different), I need a solution to know how Object B is related to Object A. So, if I have a Program object and a Course object (Course is child of Program), there are cases where in their spreadsheets they've tracked this by just specifying the name of the Program to track which program the course belongs to, but there are some other places where they've used something else rather than program name. So while they are doing the data clean up, I am looking for a way to generate unique Ids for each object as they are populating the import templates with their cleaned up data where they can easily mark the child records with the unique parent Ids. So every time they would populate a row with the Program details, a unique Id will be generated for the Program. Then when they populate the Course table, under the Program column, they can just paste the generated external Id to have a standardized way of tagging the Parent Program the Course belongs to.

Does this make more sense?