Alabama was fortunate last year, because injuries happened to positions of strength. They lost what, coming into spring would be considered the #2 and #3 running back and along with Duron never playing, they lost Black, White, and since they can't all be colors, Bell as well. If they didn't have fantastic depth, the team could have had huge issues running and passing the ball. Just remove Cooper and Yeldon from the picture and I'm not sure how the offense would have looked.
So, Alabama has already lost 4 players thus far. Yes, they were not integral, but coming into last season we wouldn't have imagined that Cooper and Yeldon would have been so important either. This puts more pressure at other positions, and a couple of positions that had season ending injuries last year had depth from one of those four players. How well Jarrick and Fowler are doing matters more now. Also, remember that pressure that Phillip transferring placed on the depth at QB.
Until we see this team at spring practice, and subsequently how this team looks after fall practice, it's really premature to arrive to a conclusion. I have high hopes, but I do have to be realistic in the sense that Alabama does need a certain amount of luck to get to a championship game.
I do have to question the basic math from the original post though. Alabama has won three of the last four, and prior to that Alabama wasn't really playing with Nick's guys. Some people would arrive to the conclusion that Alabama has about a 75% chance. That sounds a little high to me, but if Alabama can get past their first two games, I'd put the odds around there.