The disk-shaped characins are usually good with angelfish. The Rosy Tetra, Red Phantom, Black Phonatom, and a few others are in this "clade" as it is sometimes called. These tend to be quiet, and not prone to fin nipping. The Serpae which you mentioned is also in this clade, but it is prone to fin nip as you know and only shows that not ever fish in a clade will work.
The medium to larger rasbora usually work, as they too are peaceful and not active swimmers.
You generally want to avoid linear small fish, such as neons, cardinals, rummys, and the others. While there is no doubt that this sometimes works, it is a risk. Having all the other fish in the tank, and at mature size, before introducing the angelfish has been said to reduce the chance of problems. This makes sense, because the angelfish are highly territorial, and if they are the first fish the space can quickly become "theirs." As you already seem to have the group of angelfish, this is something to be very careful about.
The tank size is not mentioned, nor the angelfish group size, and obviously this has a big impact on what might or might not work regardless. If the angels have been alone for some time, say a few months, it is probably best not to risk things.
Byron.
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