Agreed. The argument is that tackles like Donald are harder to find and add that all important ability to collapse the pocket from the inside.
My response is simple. Miller has been the best tackling olb in football for years and is always a top run defender. He is also extremely dangerous vs the pass. Donald disrupts the line. And as important as that is he doesnt impact as many aspects of the game as Von.
If guards are less valuable than tackles on the offensive side then the same should inherently be true for dt vs edge player.