Alchemist 30 / Culinarian 30 = Scientist job

Armorer 30 / Blacksmith 30 = Mechanic job

Carpenter 30 / Goldsmith 30 = Designer job

Leatherworker 30 / Weaver 30 = Tailor job

They would have the ability to mix (depending on DoH) items with each other to make a greater effect think of it as a item meld.