I may be wrong but the obvious issue regarding leg lengths would no doubt be the fact that the LAX/SFO flights go over the poles, meaning avoiding most of the headwinds that the IAH flights experience. Hence DXB-IAH 17hrs (at least that was the only one I ever did). IAH-DXB maybe 14hrs. Whereas times quoted in the article above 16hrs DXB-SFO, SFO-DXB 15hrs 40mins.
So distances a bit irrelevant if the winds are so different?