Don't want to be rude, Klive, but I don't put my trust in that kind of translates; that's not "official information" for me. I was looking for a Yoshi / DEV / Moderator post.
Aside from all that have been said about the lore, maybe
official FFXIV webpage could enlighten all of us:
Thaumaturge
Death is Only the Beginning
In the hands of a skilled practitioner, thaumaturgy can be a force of terrifying destruction.
Thaumaturges are unparalleled in their powers of destruction, eclipsing even the Disciples of War.
I don't see a WHM being a force of terrifying destruction...
I know, Conjurers have elemental spells, but take a closer look to recent changes (Curaga, Raise II, Rebirth...). For me it would be odd if they tie WHM job to THM, that's all.
PS: On a side note, I must honestly say that THM's outfit displayed at official webpage recalls me of WHM, while CON's outfit reminds me BLM's outfit. Grrrrr...