Could you justify it as this place being the biggest concentration of people for a long way?
Originally Posted by tilt
So the blacksmith and leatherworker aren't just supplying the hamlet, they're supplying a few hundred people in the surrounding lands too, via peddlers and occasional trading visitors.
Disclaimer: I have no clue what sort of population is needed to support a leatherworker, but I'm guessing it varies wildly depending on wealth and quantity of animals used by the locals.
e.g. you need gear for any animal pulling your plough, or riding animals, etc...