He got exposed b/c he was on the field all the time. Not something that could be said about Morgan.
As for the comparison class:
WalterFootball.com: 2011 NFL Free Agents - Cornerbacks
That was the year of Nnamdi ... nice "no-sign". Even in hind-sight, not a lot of options better at his price.
We were losing Rogers and got a cheap starting CB. Again, we got what we paid for. Not sure what our cap was like that year, but pretty sure we weren't signing big money contracts needed to get the CBs that out played him from that class (Joseph).