Leslie, if you look at the underside of the upper wash arm, there are openings that are angled to spray against the spokes of the China Guard to help the arm turn. I am sure that they also serve to drain the arm, but since they line up with the radial supports, I think they were designed to help with the rotation. It is true that the damage done to the China Guard in the KDI58 probably would not affect performance, but if the whole thing were eliminated, the loading that caused the breakage would probably block the rotation of the upper arm completely. That was one of the great things about the China Guard; it prevented items in the lower rack from blocking its rotation, unlike in a WP where you have to check to see if tall items in the lower rack will stick up so high as to block the upper arm's rotation.