Dexter IS consistent indeed. Always in the top just like Shawn (only with a Sandow, unlike Shawn), but I think there are guys out there that are improving (winning ground on Dex) every year unlike Dex who stays consistent and therefore should fade out of the mix if you do the (non IFBB) math.
Don't get me wrong, I was happy for him when he won in 2008, but I also stay objective and find that he should be fading out if the field keeps winning ground on him without him really making the necessary improvements.
You said it right:
If Dex gets his old form back, and some others miss their mark
So you too are saying that his placing is depending on others shape whereas "the others" are battling for top spots in their best shape.
Not relevant: I hope he at least changes his posing routine and his 'irritated' look on his face as he's doing his routine to jack up the crowd.