If you read the bulk of available online articles, you'll find yourself questioning this even more, because of the "dismal" success rate with this fish. But isn't it much like the tang question? Some people do well with a variety of tangs; others fail and subsequently use their experiences as a warning to others.
My experience is rather a cautionary encouragement: if I can keep one, you should be able to as well. Coolest (reef-safe) fish ever. (And kiss your feather dusters goodbye, I think. You can get some aptasia from some other locals.
)
How territorial is your Scopas? I think you have to be aware of the animals in your care and their characteristics and temperament. After the research, it's largely an intuitive decision.
HTH,
Alan
