My point addressed the question of how two things can be the same size. Is there a rebuttal?
No, not really. You said something about sand dunes reaching some maximum size determined by the wind. What about all of the smaller sand dunes?
The smaller sand dunes come in various smaller sizes, just like the planets and celestial bodies come in.
How are sand dunes like the sun and moon?
My example illustrates a simple physical process that can result in entities ending up the same maximum size. Some examples from the previous thread on this topic:
Air-borne particles. Particulate matter floating in the air can only get so massive before it falls to the ground. The particulate matter in the air can be composed of a vast array of different materials, but only the particulate matter of a certain mass and size can stay airborne. Therefore the largest particulate matter which is airborne for a long period of time is of similar mass and size.
Rain drops. When drops are formed, they can only become so small else they are whisked and flitted away away into the air and evaporate. They can also only get so large before they break up into multiple drops by air friction. Therefore we have rain drops which can only exist in a narrow size range. The largest of the raindrops are all the same size and the smallest of the rain drops are all the same size.
Examples of forces in nature which compel bodies to be of similar sizes are seen all around us in nature, and is no coincidence.
What has yet to be explained, however, is the incredible coincidence where the sun and moon under RET have a difference in size by over four million times yet appear to be the same size in the sky.