If you are looking strictly for DoH classes that make other DoH (and DoL) classes better and easier to level, then your starting classes should be weaver, leatherworker and carpenter. Those three combined provide recipes for every equipment slot for both crafters and gatherers, save for tools and jewelry. The former comes from blacksmith, the latter from goldsmith - though I've not seen any goldsmith recipes with relevant stats among the starting recipes. I suppose those will come into play at a higher goldsmith level (I'm guessing 10+).

And I'm not sure that blacksmith is even necessary, considering the class quests throw free tool upgrades at you every five levels.