Fish suggestions - what should I add to my evo?

[baldislife]

Hello, beginner here. I have had my tank up for about 4 months now. I am using the stock filtration and upgraded the light to a fluval nano. I have some Duncan, candy cane, pulsing Xenia on an island, fox coral and plate monti as well as montipora digitata. The only fish I have is a single ocellaris clown

The clown is a bully and was nipping at the fins of another clown I had with it. So bad in fact I had to re-home the smaller one with another reefer. In a couple weeks I would like to add another fish so I wanted to ask what would be a good add. This would be the last fish for this tank. Here are my candidates as of right now:

Yellow clown goby - heard a lot of positives but will it harm the montipora?
Azure damsel - I heard they are aggressive but the azure is supposed to be the most peaceful. Is the tank big enough?
Yellow watchman goby I attached a pic of the display. Is there a enough rock work for it to live? My setup is alot more sparse then I have seen
I ruled out a fire fish as I have read they are jumpers and I have an open top.

 

[Sharkbait19]

With no lid, any fish can quickly become a jumper.
With a clown in less than a 20, any open water swimmer would be at risk. I wouldn’t do the damsel for that reason.
I have no experience with clown gobies, but any fish that stays by the rocks and away from the clown should be okay.
Any shrimpgoby will do well in that tank - they will burrow under the rock and not bother anyone. Yellow watchmans get pretty large, so I’d opt for a smaller goby in a 13.5. Look at amblyeliotris or stonogobiops species.

 

[Tamberav]

Gobies are all jumpers too... well any fish but gobies more so then say the damsel on your list. An open top definitely narrows down your choices.

A springers damsel is more peaceful then the azure, however, clownfish are a type of damsel so they could bicker.

Maybe a royal gramma?