JoeVandal, chromis are a special class of damsel, like perc clowns, that are a bit more quiet, less prone to fight IF they have enough sleeping spots. Otherwise they disappear, about one a night, until they have enough sleeping spots. If you have a lot of coral , esp. gorgonians in your tank, where they love to hang out, you might get by with a few more.
DO watch the tank alkalinity: if you have damsels and the alkalinity drops, you will see fights: as they become uncomfortable (and this goes for clowns) they get crankier and more serious about their spats.
Damsel aggression goes first for their own type, then toward other damsels, then toward other fish. They seem scarcely to regard blennies and gobies as anything but moving rocks, not a problem. I've never seen them go after one of the cigar-shaped lot the way they will something more like them. But mostly they want THEIR rock to themselves.