I’m no astrophysicist, but isn’t it possible that’s exactly what that asteroid field was in the process of doing? After all, there were several “big ones” for the Falcon to land on. Especially if there are some big collisions happening to keep all the rocks from aggregating smoothly, couldn’t there be a grace period between “cloud of space dust” and “planet” where there could be a dense field of sizeable rocks? However unlikely, surely there’s some scenario where it’s at least possible