I think you are missing my point. I'm not arguing if Nathan was good or not, simply saying that he was supposed to be on the team and closing games. There is only so much cash and so many roster spots to be had, so it hurts us whenever a starter goes out. Your argument about having depth and sufficient backup is fine and dandy, but you can only do that to a certain extent. The vast majority of your starters have to be around to produce or you're gonna be in trouble.
This team was "built to win" with its projected roster, so losing any starter for any extended period of time probably had a bigger impact on us than on other organizations who had more recently rebuilt, drafted better, or retained more of their own talent.