Well, while you guys have convinced to drop my original idea, of a player having a high chance (1/6 ish?) to find a VERY weak magical artefact every time he traded in a wyrdstone (one chance per game, with 5/6 chance of some mundane item, like a setting-based item or a lucky charm). However, I still like the idea of a higher rate finding artefacts than, say, Sartosa or Mordheim proper. Also, if the list is so long, we can say that no campaign will have more than one of the same artefact. Any further rolls of the same artefact are rerolled. (Adds a Roleplay touch, I think. In future campaigns, you can track where the artefact changes hands).
Which begs the question, this IS the Lesser Magical Artefact chart, right? If some of them seem to strong, we can bump them up to the Greater Mag. Artefact list.