At the volcano there is no tanner, taskmaster, or named alchemist (used to be by the cook). The blacksmith and cook are there and now spawn rarely, with tier I - IIIs mixed in.
There is a spot in Terrace of the Tenders that spawns always an Alchemist I and an Alchemist III next to each other.
There has never been an armorer or other professions (carpenter, performer, smelter) at the volcano (not sure if that is intended or not).
At New Asagarth in the armorer spot, I killed the thrall there many hundred times in admin mode on singleplayer and a named armorer (Njoror Battleborn) never spawns.
Fixing the Njoror Battleborn requires editing a single line in a .csv text file. At some point you have to conclude that there is somebody at funcom sabotaging the game on purpose.
What do you mean “are going to be random”? They changed the cook and blacksmith to be mixed with tier I to IIIs, however, the rest of the crafting thrall NPCs are simply gone (alchemist, taskmaster, tanner) or were never there to begin with (carpenter, dancer, armorer, smelter).