Have you ever seen a guy contesting shots with the tip of his head?
I think you have no idea what you're talking about. Hill isn't long compared to Sato, he's a midget.
People contest shots and rebound with their arms raised and outstretched. Sato reaches 8' 6.5", Hill reaches 8' 1.5". Hill is in the JJ Red tier, Sato is in the Carl Landry (yeah, the former Houston now in Sacramento power forward) tier. It's an absurd comparison. The reason Tony Allen can defend bigger players is because of his freakish wingspan that puts him at a 6'6'' standing reach. But, again, Sato is even longer than Tony Allen.