It is a thought out idea but a few discrepancies:

Enfeebling/Draining Magic (Jeweled Wand)- Arcanist (Thaumaturge)
Arcanist already exists in the lore and even Guildwise -- They do a bit more too, e.g Automata, which doesn't fit into the Thaumaturge way of things at all.

[Warrior + Arcanist] = Dark Knight (Battle Scythe)
Well, Arcanist isn't a scythe wielder nor is Warrior and Scythes are already in use with Botanist, so it depends on which iteration you're regarding -- XI's DRK was the main iteration to use a Scythe but prior to XI they also used Longswords and Greatswords -- It would make more sense if it's Warrior + Black Mage as that's what XI's iteration is with it's own set of Black Magic skills (Absorbs, Dread Spikes etc.)