On the Crows and Vessels reveal video @ 1:40 you see the 3 General Skills each arrayed in a ring around a central skill. Each one of those is a skill tree, and Thomas Blair, in the Crowns and Crows interview following the reveal, said that you must complete the inner skill-tree before training any of the peripheral skill-trees. Combat and Exploration are both five peripheral skill-trees plus one central prerequisite skill-tree (5+1). Crafting is eight peripheral skill-trees plus one central tree(8+1). Depending on how deep each skill-tree is this could be a huge endeavor - if each were as deep as an archetype tree? Then maxing all aspects of crafting could be equal in time to maxing multiple archetypes.