Attempted the challenge on ranger... Once again the character was fully runed, had mid level weapons (w/ charr mod) and cupcake.
This was significantly more difficult than casters.
Ultimately I did fail when it came to the last patrol, which stopped me from getting a good pull on Blaze. Two hours of trying and the Imp and I couldn't take out the 2 shaman 2 hunter patrol.
I recommend that anyone looking to attempt the challenge really cherry pick their spawn and rezone until they get a good one (not too monk heavy). I would also say pumpkin pie slices would help a lot...
I challenge YOU to complete the challenge with Ranger ... AVENGE Artemis!