Maybe, maybe not... It's one of those things that you won't know until you try. I wouldn't suggest it and if you really want to do two Acanthurus I'd look for two less similar looking fish. Neither fish are partcularly hardy and have a pretty poor survival rate in aquaria, so the added stress of agression between the two species just isn't a good idea IMO. If you must try it get two fish that are different sizes and add them at the same time.