We got paths within paths, here. No Man's Wharf seems to be entirely optional - which is a pity as it's a really fun area - and basically the entirety of Heide would also be optional except that you need to meet the npc after Dragonrider.
This sort of thing is all throughout the game. It's a strange structure, but creates a compelling feel of nonlinearity; I don't know any two people who've taken exactly the same route.
