15 gallon stock idea

After having bought someone’s 20gal set up a few weeks ago, I have majorly gotten the reef itch. The current set up isn’t horrible and for $80 including two black photon clowns and a tailspot blenny, I couldn’t pass it. Aqueon 20 long, tidal 35, Aqua knight A029 with a cheap 100 watt heater...

So my 15 gallon innovative marine is about cycled and I’m heading to my LFS In Pittsburgh to get fish this weekend. My plans are 2 nano clowns, one clown goby and 2 cardinals is this fine or over kill? The nano clowns are so small they shouldn’t bother the other fish I think. Any feedback would...