It's possible that I watch this division a little closer than you do. Just sayin'
The Rams are tough and deep. I'm not sure how bad Stafford's nagging arm is, won't be able to tell until he actually takes some snaps. I expect them to regress a bit from last year, call it the superbowl hangover or Andrew Whitworth retiring or whatever. Doesn't mean I don't think they will end up winning the division, I do.
I've got Arizona 2nd. If Murray can stay healthy I think the offense will be just fine. If not, it's look out Seattle, here come the Cards. I expect more from their d than you do. They have a pair of middle linebackers that will take the next step. Isiah Collins is a freak of nature and Zaven Collins seems to have sped up to match the NFL. The line will be adequate and the edge rush by committee could work. Fresh legs and all... I don't think losing Chandler Jones was the huge loss most seem to think.
San Fran is about due for another injury year. When the greatest coach that ever drew air has a losing season it's always injuries that cause it. The last 6 years he's had 4 of those injury years. The kicker here is that their D might just be good enough to carry them. If Bosa can stay healthy. If not, they are in trouble.
Pete Carrol gets the most out of his teams, but I think you are right, they are looking for a rebuild. Plus the franchise is probably for sale.
RE: NFL Season Preview - NFC West