What I tend to do is to have the structure of the Excel file in a custom dictionary (like a text input tool with two columns, ORIGINAL NAME FIELDS and DESIRED NAME FIELDS), and use a dynamic rename tool at the very beginning of the workflow, to rename the columns accordingly.
The "renaming Dictionary" may be something like this:
The Excel file (or any input file) may be something like this:
And the Workflow (And the Dynamic Rename Tool) is configured like you see here:
The results will look like:
This assures me that I'll carry all the workflow with the desired field names, and if something changes, I only have to change the custom dictionary.
Hope this puts you in the right direction.