Shrug. Density is up to the scenario writer or referee to determine.
I could see a lot more in specialized circumstances such as planetary rings.
Or, with enough preparation the battlefield could be prepped with artificially moved rocks to support whatever fleet plan maneuver.
For the scientifically literate, dense shoals outside rings push it from Sci-Fi to Space Fantasy, right there with Laser-Sword Paladins and Anti-paladins and hollyweird clips in the handles of their plasma pistols.
He understates the size.Douglas Adams said:Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space.
If you can see another rock from any given rock within the asteroid belt, it's probably orbiting the dwarf planet you're semi-standing upon (until you flex your foot and put yourself into a 10 minute suborbital path).