I think what happen with the Ravens offense while Billick was there was the same thing that happened here since the nolan era started. Too many mistakes at the QB position. Billick had Dilfer,Grbac and Boller as his main starting QBs (anthony wright,jeff blake and chris redman bridged the gap betweeb Grbac and Boller.) We all know Dilfer was asked to just not make mistakes and then was pushed out after the Superbowl to make room for Grbac who retired after just 1 season with the Ravens after playing good in spot duty for the niners. We all know what happened when Boller started. The problem is when you miss at the QB position it sets your franchise back significantly.
If Billick can get the right QB under center for the 49ers if hired, I believe he has enough creativity from his OC calling days at Minnesota to make the 49er offense a formidable one. The other offensive weapins are in place.