I have had severums and angels with danios and they didn't bother them at all. THe danios were too fast.
I have also had a severum with a few angels before and they pretty much left each other alone. Sevs seem to vary in temprament a lot. The big one I had was a gentle giant... the 2 big ones my brother had would stand up to a JD, FM, and Convict and ruled the tank.