Was he? It's hard to isolate sometimes... I dont think going by coach record is very meaningful. Really ####ty coaches with good QBs are going to win a lot more than really ####ty coaches with bad QBs.
He seemed more than competent. McNair was good but he Fisher also had some success with Chris Chandler, Kerry Collins, Vince young and Billy volek. There weren't many superstars on the team although Eddie George was great.
Personally I think he was good enough most years to keep the Rams from being total embarrassments but the game had largely passed him by the last 5 years and he just rode his prior success too long.
Basically a better Marvin Lewis.