I think you folks might be missing the point, or at least a possible point that I am seeing; It would be impossible to make all three of these completely equal. Not only would it be impossible, it would be boring.
I think the point is to have a very very slightly higher theoretical performance for one that requires a high skillcap to reach the max benefit, and one that has a very very slightly lower theoretical max performance, but is easier to reach the max benefit of. People forget or just don't realize that the overwhelming majority of players of this game are not anywhere near hardcore enough for tiny differences in performance to matter. And even for the min/max-ers, not all of them have the skill to maximize, and very few will realize max potential if they go for the theoretically-best one.
Yes, it will be mathed out, and the super hardcore will pick what is theoretically best, but they would be doing that even if the theoretical difference were within the margin of error of rng / human performance. This trend is becoming apparent in multiple design decisions for several classes/specs, and I like it. My DK may be my primary alt, but it's still just an alt, and I'll never raid anywhere near as hardcore on it as I do on my main (not that I'm "hardcore"; I just mean relatively), but I do want to perform well, but I don't have the time to invest to be great, especially when being great would make me way over-qualified for the content I do on my alt(s).