Well, I don't think any of the defensive coaches have done badly by being in Washington over recent years. Williams, Lewis, and Ray Rhodes all enhanced their reputations, I believe. You could even go back to Ron Meeks - he did well enough to move up the ladder elsewhere after his time in Washington. Dale Lindsay probably spoilt his reputation somewhat, but he couldn't blame that on his environment. Olivadotti is making a good reputation for himself during his time in Washington - and I hope he stays for a long time.
Meanwhile, all these coaches have been paid very well at the same time that they have been enhancing those reputations.
Now, on offence, people probably haven't done so well. Spurrier turned out to be useless, but it wasn't being in Washington that made him useless as an NFL coach - he just wasn't good enough. Norv Turner's rep as an offensive coordinator remained intact, even though his mediocrity as a head coach kept him away from the top job until San Diego lost their collective minds. Jimmy Raye? Well, we'd never heard of him before he came to Washington, and we've not heard from him since. Al Saunders certainly didn't enhance his reputation whilst here, but I'm not sure who he can blame for that - there was enough talent for him to work with, although depth was certainly an issue. He might have suffered from "interference" from Gibbs, but not from anybody in the front office, as far as we know (well, until he got released anyway!).
What I'm saying is that Washington is hardly a graveyard for coaches - many of them do well enough to keep moving up the coaching ladder. Yes, they often do it elsewhere, but it hasn't hurt their careers to be in Washington.
I understand Sherman Smith's reasons for hesitating, and they were family reasons. No way do I believe that a running backs coach was prevaricating over a promotion to offensive coordinator for any other reasons than family ones. It certainly had nothing to do with any cemeteries, real or imagined.
