there is no way a elemental druid can be sucessful, mostly because its skillz are far to weak. Say your main skill was Armageddon what are the odds in a duel that you'll hit someone and there not really great for cows also, it might take 10 casts of it to sucessfuly take out maybe 4, cause the radius isnt that great..
I think when blizzard made the "Elemental Skills" tree they should have realized that most of the Elemental skills just cant cut it against high hp hell cows and dueling.