Having a traditional OC guarantees nothing. If you've built your career on your offensive playcalling abilities, then play to your strengths.And only Jimbo has a chip. If you don't have a powerful defense and a top notch QB than no chips.
No the problem with Jimbo is his play calling. It's very predictable. If he had an OC to focus on solely offense he wouldn't have this problem. When he had that monster D they were able to keep them in the game. Jimbo had alot of three and outs.
Not one of the guys I mentioned would perform at a higher level handing over the offense to someone else.