I’ve mentioned on several occasions that you can win in an individual season with all the things you mentioned, but to be a contender year in and year out, you need a good QB.
That doesn’t guarantee you’re going to and winning SBs of course, but it does always put you in contention.
We see in the regular season what can happen in a single game, Arizona thoroughly beating Dallas, winless Carolina over Houston, etc. The playoffs are that much harder because all of those teams are supposed to be the best. That’s why Rodgers only went to 1 SB. Brees just 1. But those teams were always in the mix.
When the Jets went to consecutive AFCC games with Butt Fumble at QB, those teams were built like you’re talking about, but that didn’t last very long, because in this day and age of free agency and sky rocketing salaries, it’s hard to keep a team like that together.
So yeah, you can win with a mediocre QB in any given season but you won’t be consistent contenders on a yearly basis that way. You’ve got to have a QB to do that.