I'm afraid the best wind druid is a hammerdin.
hdin cant aim in a straight line.
this is roughly a difference in playstyle.
wind spells vs a circular hammer
both have great survivability. but hdin will not be beat as they can get both max block and resists. Druid have bear and dire wolves if he puts a point into them after oak. So max block is not needed for windy with meat shields.
its probably just gear reliant, not good until a certain skill level cause i dont see wind druid being good dmg until u have high tornado damage.