I hear your point. The Bears history pre-FA is so much more dominant than the Broncos history post-FA, though.
The Packers have more championships than the Niners; both Cowboys and Pack have more wins, and a higher All-Time win percentage than the Niners; the Cowboys have more division titles than the Niners; and both the Pack and Cowboys have more playoff appearances than the Niners. Which is really saying something as the Cowboys have been mid for 30 years while the Niners have been mostly elite for most of the last 15 years, and mostly good for most of the last 30 years.
In none of those categories I named, are the Niners #1 in anything, they have 0 case as best All-Time franchise in the NFC.
There's no way this would be consistent, because then you're advocating for ranking the Jets over the Browns, Vikings, or Bills, because the Jets have won a Super Bowl. When those latter 3 franchises objectively have a better history than the Jets.
The Saints have a Super Bowl win, in their only appearance. The Bengals have been to three Super Bowls in two different eras, and have been to more AFC Championships, than the Saints have been to NFC Championships. The Saints are not a more successful franchise historically than the Bengals (the Bengals have won their division more, the Bengals have more playoff appearances and playoff games, etc).
I can keep going, there are other inconsistencies if we just rank everybody with a Lombardi, over everybody without one.