Are jobs bound by lore?

[Cleretic]

Though this raises a question: If an Astrologian requires a soul crystal for their spells, how is Urianger one in Norvrant?

I believe it is actually stated at one point that Urianger is actually just using Sharlayan techniques he learned back there, and is just falling back to an already-learned skillset rather than picking up a new one. The Astrologian job we have is Sharlayan astrology, after all.