I don't know what Stew's priorities are. If he wants to maximize his earnings, then talking about career length is logical.
But you (CRA) may be right that he wants to rack up big yards as the guy and/or play on the West Coast.
I don't believe he's talked a lot about his motivations so it's hard to know how signable he is.
If he wants to maximize earnings....then taking the big payday makes sense.....As a RB you want cash not years.
In addition to that, you want to play.
Will be interesting to see how it plays out