Lee IS a better shooter than Mayo. Look at the numbers, people.
Lee: 43.3% FG, 40.1% 3-point, 82.6% FT, 53.4% TS
Mayo: 40.8% FG, 36.4$ 3-point, 77.3% FT, 51.3% TS
In fact, Mayo is not a very good shooter, and Lee is an above average shooter.
Lee is also a better defender.
Mayo's advantage is that he is a better rebounder and passer.