The problem with a 2" tire on super-loose sand is that it can be too floaty to slice through the surface, but not floaty enough to float. Then it just sort of wallows, aimlessly and sluggishly. I use that tire on my gravel bike, it's blazing fast on anything that doesn't break up very badly beneath it, but there's not really any way to get it to behave well on mud or bad sand... it wouldn't really surprise me if it was a significant overall advantage on that particular course.