I've never had an orchid dottyback but from the research I've done, they will attack shrimp so, if you have any be careful or they could be an expensive snack for the dottyback. I've also heard that they get a bit aggressive. Again this is not first hand knowledge.
I do have a blackcap basslet and my experience has been that it is a very hardy and peaceful but shy fish. It will stand its ground but, generally gets along peacefully with a pair of percula clowns. A very beautiful fish, IMO.
Miles