i think with a pair of clowns, 2-3 damsels and a royal gramma in a 24g tank you'd have BIG trouble. you'd probably be ok with a pair of clowns and 1 damsel in that size tank.
Buddy of mine (well, not a buddy anymore because he's a flake) had a unique solution for removing damsels from a cycled tank given they are so hard to catch. After the tank was cycled he'd throw in a picasso trigger, and not feed the trigger. End of problem (and damsels).No matter how many experience encounters you've heard, damsels + other tankmates are strictly case by case scenarios.
I disagree that dominoes are less aggressive, they are notorious for being one of the most aggressive.