They were later reintroduced in Bloomburrow as simple occupations talents like fisher, builder, blacksmith, and the like, then again in Teenage Mutant Ninja Turtles to add depth to some of the main characters from that franchise
The rest, along with their subtypes were simply for flavor
This was originally marketed as a side deck, including reprints of several cards and sold for half the price of a standard deck
Please note that word is "play" so it works for artifact lands or dork lands like Dryad Arbor
Bogardan Hellkite, Burning Sun's Avatar, and Inferno Titan are all great cheap ways to go about this
While I expect it will be my least-played of the bunch, I can always dip into the staples suite to beef up Gahiji or Roon