How did he get dwarf angels? I thought they all got to a good size unless stunted.
A mate of mine had an angel and all sorts (guppies, tetras, swords, platties etc) and after a year he only had a huge angel left alive it ate eveything else.
Angels are cichlids, they are aggressive, predatory and they get relatively big so be careful with how you stock them and make sure your tank is big enough. I have actually found them to be quite horrible to keep, I have only just got a few more with 10 albino angels growing out nicely.