Unless I am crazy and missing something, you are leaving out that the ranger with highest amount of pks (divulged through pbfs) was a mountain/beastmaster (Nreeishe). In fact, it really looks like you are seeing what you want to see when I take an objective look at the data.

Top 10 List (By PKs - coincidentally, only rangers with > 100 pks)
1. Nreeishe Mountain/Beastmaster
2. Paraloiut Marsh/Explorer
3. Nyst Marsh/Savage
4. Sulye Forest?/Explorer
5. Iklahn Bedouin/Savage
6. Rasst Marsh/Explorer
7. Krynna Cavern/Beastmaster
8. Azhelak Marsh/Explorer
9. Garm Forest?/Beastmaster
10. Tjok Forest?/Survivalist?

Not absolutely positive on the one with the ?, but I think that is correct.

Sticking to pure terrain, we see this trend.

Explorer: 4
Beastmaster: 3
Savage: 2
Survivalist: 1

This kind of hints to me that beastmaster can't be that bad.