Secondary as a total unit, Nnamdi doesnt make the secondary, lol hes just 1 person, The 49ers have 2 pro bowl caliber Corners and a pro bowl caliber SS, plus quality depth.
And for the Tight End situation, catching isnt everything, Vernon Davis has shown to be a great blocker as well, he has to work on his catching though. Andy Lee was the best the year before last, and this last year he had a few better stats than Lechler. And its not the 74 yarders that Seabass misses, its the easy ones that he misses. 49ers special teams units also had a few KR and PR for Tds, but also blocked punts and kicks, some of which were returned for tds