It seems every level is getting the top encounter at the Wandering Dunes. I went to check this with my level 5 PC.
And he spawned one witchdoctor and six duneleapers. Same spawn as my level 13 PC, who used to spawn three duneleapers. And yes, this was his spawn, it was verified.

I understand that the challenge in the caves has been upped a bit because of the resources. But this was the only safe path from Prantz to Audiria. The other takes you through bugbears, who are even worse.
I think PC's who do not have the advantage of sneaking or invisibility should get a decent chance to get past this area solo.