There in lies the problem. No one else has ever paid a RB what the Cowboys paid Zeke. RB's are not worth that, they take too much of a beating and get hurt and you can have someone else come in. If you paid someone 1/2 the amount of Zeke what could you use that additional $$ for in getting your team better?
When a OL goes down you will get more return by have a better back up than you will paying a RB the money they are paying Zeke.