[DJ88]

Your tank will be seriously over stocked. With any of those combinations.

In a 120 I'd say 10 chromis might be ok. not that many damsels or clowns. They will kill each other. IMO IME

Damsels in the wild live in a space of about 1 cubic meter EACH. And they defend this territory aggressively. Once the percs mature you'd have another fight on your hands. I have seen three in a tank together. Most often more than two isn't recommended of any fish of the same species.

Damsels adn Clowns AREN'T schooling fish. Or even shoaling fish. When they are juveniles yes they will stick with each other.. as they grow no way.

I have had a small shoal of chromis and they even took each other out. slowly but surely the smallest one gets picked on till it dies. Then the next and so on and so forth. It dowesn't always work this way but the norm seems to be like this.

With your Tomato clown you'd probably be looking for more trouble. They can be quite belligerent.

If you ask me you are looking for trouble with numbers like that.