i read you can keep coral beauty angelfish together - yes
as long as you have 3,, i have 2 - i have seen pairs and harems of this and other centropyge
and i have heard that they are mild enough that with enough room 2 would be fine,, well? how much room is enough room? They're not that mild - if you get two that are incompatible you will at least 6 feet of tank lengh, probably 8 or 10 to be safe. The key is to et a compatible group of 1m1f or 1m,2or more f. All centropyge start life as females, and then the dom,inant one in the group becomes the male. I am unsure if you have 2 males in a groupp, one reverts, but anyway if you have 2 males in a tank the dominant one will kill the other (lack of space to hide). So to get a group, normally you buy 3 or 4, all small and let themselves sort it out.
I would not advise this in a 55 for example, you do need a decntly large tank to help out, although if you can get these at say, 3/4 or 1 inch then a 55 might well be large enough. I have never tried and so am speculating.
Putting 2 together is basically guessing. You might get two males (one dies), 2 females (ok), and then one goes male, or you might get a male/female that are compatible, or a pair that fight.
If I had a pair, and they were ok I'd lave them be I think. Some people advise adding a 3rd, very small, to beef up the pair band, but in a small tank I think it's risky.
Next year I will try to get a trio of Centropyge - I hadn't really though of CB's, but they would be a good option. I was thinking bicolors or rusties
