Dak's injury is not an excuse, but anyone who thinks any team can lose their starting QB and win consistently is full of it. And, it is not just Dak. It is their 3 best offensive linemen and a backup to one of them. I don't understand why people excuse the Eagles and 49ers because all of their injuries but then say it is not an excuse for Dallas.
Look at Washington and NY. Washington has 3 name guys on their IR, Kyle Allen, Landon Collins and Matt Ioanidis. Allen replaced Haskins, but it is clear no Alex Smith is the best QB on the Washington FT. Collins is a quality player and a starter but Ioanidis is a backup DT. That's really it for them. No injuries to their starting offensive or defensive lines.
NY has Barkley, Kyler Fackrell, Lorenzo Carter, and Devonta Freeman on IR. Those are their name guys. Danny Jones has a hamstring injury and will miss one, maybe two games. Their entire offensive line is healthy. The same it true for their defensive line. They are banged up at LB, but the rest of that team is healthy and has been for their 4 game winning streak.
The Cowboys are missing 5 starters on offense, including their 3 best offensive linemen. They have during the season had their backups to their two offensive tackles on IR as well. They also had their starting C out and his backup out though not at the same time. The Cowboys have had 3 of their starting CBs out, 2 were out last week and 2 may be out again this week, along with their new starting Safety. Tell me the Giants or WFT would be in first place with that many starters missing time? The 49ers took a nose dive this year too because they are banged up on the offensive line and at CB. The Eagles are in the same boat. The Steelers lost a couple of guy on their OL and lost to Washington. The Seahawks lost a few guys on their OL and lost to the Giants.
The old expression is "everyone is banged up this time of year. But that is not really true. A lot of teams have injuries here and there, but some teams are missing a lot of starters and it does make a difference. It is idiotic to say otherwise. If teams should still win with backup players then rosters mean nothing.
I have no doubt in my mind that the Cowboys would have won the NFC East easily if they were as healthy as the Giants or WFT. They would win with Dalton if they have Tyron Smith, Zack Martin and La'el Collins. They would win with Erving and Martin, as they did in Minnesota - despite their horrible defense. They would probably go 9-7 but they would still win the division.