Furthermore Koobs had to watch his QB implode in historic fashion. Koobs strength is X's and O's way more effective, creative and proven variant of the WCO/EP type systems. He understands that linemen are important especially in the ZBS.
His biggest fault and what ultimately led to the fire IMO was loyalty. He couldn't fire his guys when they needed to be, he held onto players past their shelf life
I still throw out the team that Kubiak took over and how he was able to grow the team into a winner while working with Smith.
Obrien took over a better nucleus was nowhere near the same rebuild and his record is mediocre, his offense much worse, luckily he chose a great DC and didn't go with the buddy system like Koobs mistakenly had a propensity to do, but yet his failures have a habit of being aimed at Rick Smith and he needs more time with Gaine. But if Smith was that bad how could Koobs win with him? Coaches have more input in personnel than some are willing to admit.