I think Jamaal is a closer 2nd than you think. Sure, Luke wins the Doak Walker Award, but you have to consider a few things before putting him so far ahead of Williams.

1. Luke's O-line was better than Jamaal's.
2. The 2001 schedule was softer than the 2016 schedule, so Luke's stats are a little more padded than Jamaal's.
3. Luke had more talented teammates on offense (Several NFL draft picks around him: Doman, Jolley, Mahe).
4. Jamaal produced more consistently over 4 years.
5. Jamaal was a vocal leader who lifted his teammates as a team captain.
6. Both have fought through injuries, but Jamaal got drafted higher than Luke did.

I think that Luke had the best single season of any BYU RB. But the greatest all time at BYU? That's up for debate on many levels.