I really don't like Riley at all and Clay is ok I guess. You are pretty much right though. They are both there to take finishers so Del Rio and Miz don't have to.
Every time I have watched him after NXT (granted that it is not a lot), I have seen him lose the fall in these tag matches, on Smackdown, he got Speared, and almost every Smackdown before WM, he was taking the hits, not Del Rio.The difference is Clay doesnt get owned every week...