I'm not sure that it's necessarily fair to look at raw numbers, when Lebron has played 4 games and Rondo has played 5.
Rondo: 24.2 ppg, 10.2 rpg, 10.2 apg, 3.2 spg, 2.2 tpg, 51.1 fg%
Lebron: 32.0 ppg, 11.3 rpg, 7.5 apg, 1.5 spg, 1.5 tpg, 50.6 fg%
The numbers are very close, but I think the additional 8 ppg that Lebron adds are probably more significant than the leads Rondo has in assists and steals. Of course, the most compelling stat in Lebron's favor is "4-0", but Lebron has done everything he can.
As mentioned above, though, the players play different positions, so different things are expected of them. It's more impressive for a guard to be averaging 10.2 rpg than it is a small forward, and it's more impressive for a small forward to average a ton of assists than it is a point guard, etc.