In fact I've just checked their averages and they are identical which confirms it for me.
Averages aren't everything.
Over the past ten years batsmen have been on top, meaning plenty of players have averages over 45 and even 50. Batting's been easier.
Michael Atherton's average was only 37.69. Ricky Ponting didn't have to play most of his Test career facing Ambrose, Walsh, McGrath, Donald, Pollock, Wasim, Waqar, plus Warne, Murali and Kumble.
I understand your point but comparing Ponting to Atherton is well just lol. Ponting deffo has played a lot against Pollock, Murali and Kumble. His test debut was in 95' which is only 4 or 5 years after Lara and Sachin the 3 are deffo comparable.
For me I would have the 4 best batsman of the last 20 years as Sachin, Lara, Ponting, Kallis and then the rest in that order. If I wanted someone to save a test match for me, you could almost reverse that order but with Ponting first (throw Steve Waugh in as well).