I love your cartoon drawings....
adding on...
The damsel you drew has the another name called the tank wrecker.
Because 90% of us had to tear down our tank to catch him because he was being a complete jerk and we could not add anything.
The Splended and Grama will not live peacefully in a tank that large, and will start a holy inquisition to eradicate each other.
The clown, if it starts hosting something, it will stay in that zone, and kill everyone that comes into its home like a old man with a shotgun watching his porch telling people to get off his lawn.
The file fish is very tough to keep in a tank that small.
Most are very picky eatters, and most reefers only house one temporary, because they one of the solutions for aptasia removal. If you can get it to eat mysis, your in luck, but most rather eat aptasia, and sometimes even your expensive corals.
I have a breeding pair of Bangai.
They are pretty chill, as long as its not another Bangai...
To be honest, id keep a 20gal as peaceful as possible.
So id would do something like 2 Juvi clowns and hope they will pair, and one will transition.
A Yellow Goby, or a Clown Goby, or a Warpaint Goby... these guys are cool as they like to pearch a lot.
Maybe a Bangai...
And the LAST addition... this guy needs to be last... would be the Grama, or a Orchid Dottyback (Pseudochromis fridmani) Make sure its a Orchid, and not a purple... as they are worlds apart in temperment.
Also that Orchid and Grama will seal your tank making sure you can't do any new additions, except replace the exact same fish for fish that may happen to die.