When I got my new (used) 30 gal. it came with a blood parrot, a convict, and a cobalt. The blood parrot is fine by itself, I think. I don't know much about them cuz I've never had them before, and I don't know what they are like in groups. But this one seems fine. He wanders around the tank exploring and digging around. Him and the convict have become buddies (the size and color difference is amusing when they swim around together) and they both try to gang up on the cobalt. But they hang out together (literally) and are always found in the same corner.
I guess what I'm saying is that maybe they are schooling fish, but it seems like they can make good good buddies with other fish, so if you add a few different kinds of cichlids (don't think the angels would count in this situation) then your blood parrot would probably make friends with some of them.
Good luck!