What do you see as a Sylvan setting?

A mystic, ancient forest?

If so the the Tribesman could be a wanderer.

He/She could be a scout from a hunting group or could be a scout for pilgrims going to a holy site.

Could be a human tribe that lives in the forest.
They could be enslaved by a green dragon.
Or worship an old treant.
Or be the scouts of a human army who is coming to harvest rare wood in a hostile forest.
Or be the lone survivor of an adventuring party.

There could be a ton of reasons. You can justify damned near anything if you try hard enough.

In the past I've randomly selected power levels (using playing cards, each suit being a faction and a card drawn to show political power, personal power and loyalty, the higher the card the higher the value) for various towns and villages in a small kingdom and then figured out why those power structures came to be and how they interacted. It was a pretty fun way to develop a little kingdom.