Think about it....for a jump ball, you have to first make sure you have the correct players jumping. Then you've got to line the rest of the players up around the circle. Then you run into problems like lining up the players the wrong way, bad tosses, touching the ball before it's reached it's apex.
With the posession arrow, you look at the table, point the direction of the arrow and take it it out. That sounds pretty time conserving to me!