Are Grey Knights Idiot Proof? A Semi-Scientific Experiment

This started off as a joke between Adam and myself.  I've been a long devout Xenos (Eldar and Dark Eldar) player, and have recently hopped the fence to start a Draigo-based Grey Knight army.  The play-style is so completely different than my Dark Eldar that it provides some interesting challenges.  Unfortunately Adam has not seen the light (grey) and insists that the Grey Knight Codex is evil incarnated in Warhammer 40k game-breaking form.  Of course, I completely agreed with him until I began playing Grey Knights myself.

The hypothesis (courtesy of disgruntled Hive Mind Ambassador Adam B):  Grey Knights are such a point-and-click army that you could randomize which direction they move, randomize who they shoot and assault that they would still be victorious, or at least be highly competitive.

The experiment: Using my shiny new Draigowing army, I will indeed use a scatter dice to determine the direction I move, and will randomize who I shoot at based on what I determine to be in range.  If nothing is in range, I can run (in a random direction, of course).  A "hit" on the scatter dice allows me to choose the direction, and I don't have to move if I don't want to.  The initial tests will take place in small game settings (1,250 to 1,500) as I am still getting used to the army itself.

Thoughts: These are obviously pretty harsh conditions for an army to perform, but it will be interesting to see if the list is strong enough to suffer through completely randomized movements and shooting to still be competitive.  My personal belief is that Grey Knights have one of the top codices available, and have all the tools to be competitive.  However, to truly be a top tier army, they require a certain amount of symmetry and tactfulness, similar in style to Eldar.

Stay tuned over the next few days for the results of this "experiment".  In the meantime, what do you think?  Are Grey Knights the poster child for point and click playability, or do they require a certain skill to maximize their effectiveness?