His peak is only better if you consider SR, or designate a peak length designed to better suit him than the others.Ponting gets ahead of Sanga/Kallis based on super high peak and peer rating moreso than SR.
His higher rating is only due to peaking earlier (which obviously should be meaningless) and his SR.
Unless you apply whatever peak length you are picking for Ponting to every player you rate, this reasoning loops back to SR entirely.