I never had issues with the orchid dottyback I kept for a few years (alongside clams shrimp and mandarins for that matter). They are the least-dottyback-like of the dottybacks at least as far as temperament goes (I guess they are still dottybacks ultimately).
I don't know how a trio would behave though. .. I dunno, hard to say.
The problem is if you cross fish off the list because they "might" one day become a problem to something else you potentially want in the tank .. you end up with a mighty short list.
That said, I know I wouldn't want a sixline wrasse ever again and it's the same reasoning Madreefer uses, and I totally tell people not to try one if they ask me if they should, so I totally sympathize with that notion. Maybe they are better off in a nano type setup all to themselves.