Jamaal's Sr season was the best season between the two of them so I tend to put him just slightly above Harvey. If Harvey had a Sr season I think I'd have him above Jamaal because of his consistency and durability.
I lean towards Staley as the GOAT though because at his peak he was clearly best.
Interesting thought. If Taysom had been injury free I think he would have been right there with Staley for top "rusher" of all time.