It's not the only thing I judge Jamaal on but it's one of the factors IMO.
True, the Utah teams Jamaal faced were great at run D, ranking 23rd, 20th, and 22nd.
But so was the one Luke Staley annihilated in 2001 (24th). Two of Harvey's Utah defenses were average (53rd in '07, 54th in '09) but the one he gashed in '08 was ranked 11th.