Hi Mark,
I too have read mixed reviews. From my limited knowledge of the species, I understand that they can be kept in small groups even though they are sometimes described as aggressive. Whether this is only towards conspecifics or other fish, I don't know. I have a blue damsel which has been nothing but peaceful to all tank mates, despite being described as semi aggressive and territorial. Given a good amount of tank space and rocky hiding places, I wouldn't have thought that a group of 3 to 5 would be too much of a problem. They are also considered reef safe. I forget what size your tank is?
Anyway, hope that's of some help.
AK