I don't think it would be fair to add two of these fish to a reef aquarium. You have a 50% chance of having 2 fish of the same sex, virtually guarenteeing the death of one of the fish. Even if you have a male and female, there is a good chance that one will end up dead.
following your next paragraph of advice, i would have to agree with this statement. however, i think your next paragraph is 100% wrong
, therefore, i don't agree with this one either
If you do want to try this "experiment" you should add the fish to a tank with no rock, so that you can remove one of the fish if necessary.
adding 2 fish of the same species into any tank without hiding places is asking for one to be killed and i would consider this very irresponsible behavior on the hobbyists' part. there should always
be hiding places available. for this particular species a selection of 5 or 6 pieces of 1/2" PVC cut into 6" legnths works perfectly. it allows for the dottybacks to hide from one another, thus reducing the stress. if one does need to be removed it is very simple to lift out one of the PVC sections while a dottyback hides within. this reduces the stress of having to net the fish and remove it from water. in the event that your dottybacks do spawn it will make collection of the eggs a cinch.
even with rock in the tank it facilitates an easy removal if need be. i'd rather lift a piece of LR out of my tank then chase the dottybacks around with a net in hand.
even now, after repeated spawnings, my P. fridmani
will still chase each other. more like the male chases the female. IMO, in a tank without decoration this pair would not exist.