The impact can often leave a rim around the crater. This has certainly happened on Earth. As a result, erosion produces a bias in the relative number of big to small craters. The cratering rate may change with time. In fact cratering may have occurred much more frequently in the far past than it does today.
Craters can 'saturate'.
If the cratering rate is very large, craters can become overcrowded, meaning that new craters can be made on top of old craters. We think the Moon is very old, like 4.5 Gyr. The chemical composition of the Moon and Earth is similar but not identical. There is a near absence of any iron core in the Moon. The Moon's orbit is inclined to the Earth's equator, somewhat inclined to the ecliptic, and the orbit is prograde.