The Niners got lucky last year, and so did the Seahawks. I will admit that Rams took a step back. The reason for their step was self inflicted by financial decision. They did not want to pay Roger Scaffold and Ndamukong Ngwa Suh.
This would have an impact on both offensive and defensive line. Throw in the doubts about the health of Todd Gurley.
This year the depth of the offense and defense especially the strength of the rushing defense will make a difference.