I've been watching football long enough to know that predicting a specific number is folly. Way to many factors.
I think the line of 8.5 games is about right. 8-9 wins. That's an average season from this team as it's constructed. The most positive outlooks are ignoring some faults (passrush? Murray's struggles with out DHop) and the most negative are not considering the strengths of the roster enough.
I think the defense is around league average, but could be better if one of the more unproven pass rushers or two step up.
The offensive line isn't good, but Murray avoids sacks others would take more often than not (even though Murray runs into sacks that he shouldn't).
The strength of the team other than at QB, is the skill positions. The Cardinals have a solid starter at RB and some hope that one of three players will step up (Eno, Ward, Ingram). Wide receiver even without Hopkins is pretty solid. Tight end went from a position that was a negative going into last year, into a position that should be a strength. The Cardinals can throw out Hollywood, Moore, Ertz, Green, and Conner on most plays and there is enough size and speed to cause defenses some problems. And when Murray is on his game and running around, the Cardinals will likely have three players on the field with 4.3ish speed at the same time. Few teams can boast that.
The offensive line isn't a great group, but as Cardinals fans, probably 80% of their lines throughout the Arizona Cardinals era. It's no the disaster that some portend, but it's definitely not a strength. The Cardinals do have some proven depth that have played in the NFL (Murray, Jones, and Harlow) and that's more than quite a few teams can say.