What is this?
I define your Career as making one of everything, and gathering those items yourself.
Imagine that you are leveling Blacksmithing. Just how many Bronze Ingots do you need? Imagine yourself out Mining. How many Iron Ore do you really need?
There are items with multiple recipes (Bronze Ingots are made from BSM & ARM for example). Due to the complex nature of the calculations, items were simply split evenly between those crafts.