We do not really know just how much dark matter their is, let alone whether all of it is in real matter or in exotic particles. What we do know is that, in those places where we see unambiguous 'dark matter' indicators, such as clusters of galaxies and galactic halos, the dark matter seems to be clumped nearly the same way as matter. It seems unlikely that on cosmological scales, that the dark matter distribution would be perfectly smooth. In fact, galaxies are said to be tracers of the largest density fluctuations in the dark matter distribution, and in galaxies we see clustering at many scales.