Exact timing, including air resistance, is far more than what’s required. Sure, everything about the orbits needs to be almost exact, but the fact we can predict exactly how the craft bounces about in the atmosphere, which is turbulent, and predict the landing this accurately is insane. Landing on the moon, on the other hand, is a lot easier to predict. A high school calculus student can calculate that, and orbital information, down to the second if they have the starting conditions.