Restricting places where See also and Classify looks for relevant material

This seems to be much less useful than I had hoped, which makes me wonder whether I am using it correctly. I have a large database, of nearly 70,000 pdfs. From them I manually selected 50 to 100 on a particular topic, and then I hoped to use See also to locate further references that might be relevant. The problem is that See Also lists only files that are already in the Group I have created. OK, it reassures me that my manual selection identified the key documents, but my goal is to locate other materials that from groups that are less obvious and which I might have missed. Is there any way to force See Also to look only outside the group in which the “source” document is located? Alternative, an option to tell See Also the Group in which it should look for other relevant files?

Also, is it possible to use the classify option only when new items are brought into the database, and not for ones that are already there? My goal was to have all documents listed in a Group, call it “Source”, in which documents are grouped according to where the original comes from, and then have another group, call it “Topics” in which Replicants are sorted according to topics. I had hoped DT’s AI technology would help with the latter.

How large are these documents usually (number of pages/words)?

The See Also & Classify inspector supports only documents but not multiple selections.

A smart rule could classify items on import.