I love discus and have looked up lots about them as also was wanting to have them in a community setup but have been advised not to do that.
I have seen people keep discus with angels before and know lots of people do stuff that others would not recommend. Seems to work for some and not others.
I was told discus can be skittish and wont like being spooked by other flighty fish, dont like strong currents that other community fish might like, need heavily planted setups and need higher temps which may not suit others. Don't like to be on there own, are expensive and sensitive so I wouldn't like to spend all that money on a large group of discus if I wasn't sure they were going to mix in my community setup as beautiful as they are.
That is just my take on them by what I have researched and been told.
Angels are not community fish, I always assumed they were because others kept them in community tanks but they get nipped to bits off other fish look rubbish and become aggressive towards the rest of the tank when breeding and will force the rest of the tank to the other side when guarding eggs. So not the best idea for a peaceful community tank.