You're assuming Nnamdi even wanted to play here, & you're also assuming he would've take the same deal he got with San Fran with any other team.
Nnamdi took that deal with San Fran because: A) San Francisco is a Superbowl contender, & B) wants to get back to California where he graduated High-School, played College football, & played 8 seasons with the Raiders. He's lived in California most of his adult life, & I'm assuming he probably likes it there. That's probably the only reason he took such a team friendly deal is because he was most likely dying to get back to California.