Our best regards to 82games.com, Lee has allowed opposing power forwards to score 21.2 points per 48 minutes against him this season. Landry has allowed only 18.9 points per 48 minutes, albeit on a higher eFG% (meaning teams like to attack Lee more than Landry).
It's really just the rebounding that remains the huge dropoff from Lee to Landry. But even that comes with some caveats. David Lee is one of the top defensive rebounders in the league, collecting 24.5 percent of available defensive boards (16th-best in the NBA). Landry, meanwhile, collects a serviceable but not extraordinary 17.3 percent of defensive boards. For a team who prides itself on defensive rebounding percentage with the top defensive rebound rate in the NBA, that's a blow that you can't glance over.
But that's only on the defensive end. Landry is actually slightly better in offensive rebounding, collecting 10.9 percent of available offensive rebounds as compared to Lee's 8.5 percent. That makes the total rebound discrepancy more manageable, with 16.8 percent of all available rebounds for Lee to 14.2 percent of available rebounds for Landry. It's not good to lose, but it's also not inherently series-losing in and of itself.
I know, losing the second-leading scorer and leading rebounder hurts. We're not going to argue that, if for nothing else the morale loss that it comes with. By the numbers, though, the loss isn't that bad. What little chance the Warriors had of taking this series will only drop by a tiny bit, and Carl Landry will serve as an adequate replacement.
You should keep feeling stressed, Warriors fans, but David Lee shouldn't be your main reason.