The only thing for certain is situations, and they usually are a better indicater of potential than talent.
Situations change almost constantly. Talent remains until father time comes calling.
True, but talent can go wasted a lot easier than oppertunity IMO.
Name a great RB in recent years who has never eventually gotten a shot at a starting role.
Starting role is not the point, starting role on an efficient running team is.
If that's your stance, then who's to say any of these teams will remain efficient? Maybe Manning will start getting concussions and retire. Maybe Shanahan will get fired and replaced with Mike Martz. Maybe Deuce McAllister will get hurt in a car wreck.These are all unlikely scenarios, but the point I'm making is that there's plenty of instability based on situation. What may look like a great situation one year can look horrible the next year. It happens all the time.
Things change very quickly in the NFL. Systems come and go. Supporting casts come and go. It's foolish to bet on opportunity and a perceived "friendly" system because those things typically don't have the staying power that good talent does. It all comes back to my initial point:
Good players make opportunities. Bad players squander them.
Drafting is an imperfect science. You'll never be able to perfectly predict the future, but I think betting on talent is clearly the wise move in the dynasty format. Rarely will a truly great player fail to make an impact due to situation limitations.