On the one hand, I don't think Shula or anyone else should be ok with how things turned out. The team fell short. Sure, the talent was lacking, and we can't expect Shula to concoct some whacked Fritz Shurmur-esque bullshit scheme to compensate for the lack of talent, but the team fell short. Once coaches start feeling ok with falling short, we're on the way to 7-10 seasons. Also, that silly off-season narrative that the Rams didn't sign a CB because of all the CBs already on the roster seems to have (deservedly) bit them.
On the other hand, this team was Charmin soft versus the run last year. Kudos for fixing that. It's currently a young and cheap unit with lots of room for improvement. With or without Shula, the D is something we can expect the FO and McVay to address this off season.
On the other, other hand, multi=SB winning DC Matt Patricia is available.