"Added code to find and eliminate duplicating articles across multiple feeds (i.e., the same article showing up in Business and Investing)"
If you run the recipe without this and with it you will notice that when it deletes an article it also deletes the article below it that does not occur anywhere else so you actually lose articles.
Also
All this did was get rid of the links to the rest of the pages but did not add the rest of the article from the other pages