Variety and Similarity

Is one purpose of the archive is simply to preserve the variety of any given age?

This question about variety led me to consider what similarities might exist between journals that would seem to be in opposition to one another, for instance, a self-proclaimed "conservative" journal like The Owl and a undeniably political journal such as The Egoist. Thus, I took three issues from each journal and, after putting them into Voyant Tools, subsequently took a look at the terms they have in common, featured below: