From a design perspective, having two functionally identical cards allows you to bring redundancy to this archetype.
I didn't understand a word of that article.There was once a guy who ran a blog in this style for designing Vintage decks. He referred to them as "e-books" and wouldn't write the next one until someone donated $1.
http://topsecrettechnology.blogspot.com/2011/02/e-book-about-ichor-wellspring.html