In my current game I visited Trynton but didn't bother heading up to where the Rattkin were yet. Instead I continued on into the swamp. The Dark Savant appeared and complained about being robbed then left. When I later went backs to the Rats they said they'd robbed the Savant already. Aside from the question of how it occured to me to wonder about the Savant's trigget location. For me he will appear if I follow the swamp road west until it turns south, if I go slightly north from there he will appear. But it's possible to avoid that spot entirely, even if you just stick to the road.

Are there other points where the Savant will appear or does the game expect you to stumble onto that one location. It does tend to attract your attention since there is a signpost nearby.

He appears in a greater area of the swamp ( mostly in the western part around the exit to Trynton).For me he appeared from the sign "Danger Swamp Gas" north of the way up to the area half way south to the tar pit.

There are some cracks in the swamp, as well of several dark spots. If you walk very close to one of these places, dark savant will appear. If you avoid the spots, chances are that you will run across a crack later in the game by inciddent. Or you explore the one with the signpost, as you did.