An all-damsel tank can be quite beautiful, and honestly, in keeping one, I never knew a damsel to do more than chase, which they do often, but not far from home. They WILL kill members of their own kind; but if you only have one each of damsels and enough room to let them run (they do need space) there are few fish on the reef more variedly colorful and so in motion.
People continually plead for 'schooling fish." Well, if you want the behavior, just get one of each sort of damself, plus a small batch of 1-5 chromis, and turn them loose in a 100 gallon tank. I got a lot of oohs and ahs for that tank, and they were all very inexpensive fish in really fat, good condition, not even a frayed fin in the lot. They're masters of the big demonstration without laying a tooth on the competition. They defend 'their' rock against all comers---yet I never had them bother any of my other fish, including mandarins, scooters, gobies, etc.
Lol! The 'boss hog' of my tank was a near 5" blue velvet with an attitude. Nothing gave it grief.