You know what's funny? I meleed a few of them to death by smacking their legs!
One thing I find really odd is just how much damage their legs can take before finally breaking apart. I pretty much have to use my DAHL burst-fire sniper rifle.
Playing as Salvador that's all I do with them. Not even worth bullets. Smack them three times and they go down. And drop some money in appreciation of my badassery!
Though honestly I read somewhere that they are weak to melee and that works the best for me. I am overleveled to the area, plus I have some points in a meleee skill so I am sure that is helping alot. Haven't tried it with Maya or Axton.
Did you find the minecraft level in the caustic caverns yet?