Map fields automatically

I have no clue how I'd achieve this, but I thought it was a neat idea.

The basic premise is that based on the PDF field keys, or maybe the labels, the user would be shown a list of matching tokens and could check off which ones they wanted to keep.

This is initially for purposes of discussion. Would anyone want this? Can anyone think of how to implement it? PDF field keys are often very different than node/webform field names, so matching them wouldn't be easy. It might be more work than it's worth. But I guess we'll see.