I don't know how it works with CM, but back in the day, I generated a lot of maps using 8mm6a. With a clean random_maps folder, the resource spawns are indeed more evenly distributed and the maps are more playable. I know it sounds strange, but that's just how it is...
P.S. In Heroes of Might and Magic, with AntiCheat enabled, maps are not created in the random_maps folder.