indivual elements of dark matter have different fundamental properties from what you might construe as fundamental behaviors or properties of dark matter in aggregate. Quite a few features have been ascribed to dark matter both on the individual level and aggregate. Thus far, it has only been detected (as such) on the aggregate level, so the rest at this point is really not much more than educated speculation. Yes, there is obviously a leading theory accepted by a large majority of cosmologists on what dark matter is, but the reality is that it is far from well understood. The fact that galaxies appear to form without dark matter is very interesting, not just to the science of galaxy formation, but to our understanding of dark matter itself. Seems weird you would deny that, but whatever.