From the preview, Bill Williamson's depiction seems pretty spot on. He feels depreciated and eager to prove himself in order to climb the gang's ladder.
Bill, in 1911:
Bill Williamson : You must think I was born yesterday. You always did think I was an idiot.
John Marston : That ain't fair, Bill. You were as my brother. I've come to try to save you.
John Marston : Bill, please. They want to kill us all. I can help you.
Bill Williamson : Well, you never tried to save me before. You only seemed to save yourself.
John Marston : Bill, I implore you, think about this.
Bill Williamson : You implore me? You implore me? You always were one for fancy words. Well, things are different now, John. Now, I'm in charge! No more Dutch, and no more you. Implores. I, I implores you to go back and tell them to send someone just a little bit more impressive next time.