Don't add Mandarin Dragonet. The Dwarf angel the Halichoeres wrasse and the 6lines wrasse (if you disregard my warning) will eliminate pods in your tank and will result in a starve Mandarin. In smallish tanks, you should not add Mandarin in a tank with other pod hunters. In this case, a fat Mandarin will starve after about 6 months.
I’m going to disagree with you on the “In smallish tanks you should not a Mandarin with other pod hunters”. And the reason for this is;
Most other pod hunters will wait for their next meal and so doesn’t eat as many pods.
Now, I know that they do still eat pods and obviously will eat a few pods in a day however, if the OP is able to introduce pods weekly then their colony should build and build. I get small bags of pods from my LFS on the weekly basis, each bag has Atleast 100 copepods in it. I buy 8 every week (which is an estimate of 600 pods for the 4’ tank and 200 pods for my 3’ SPS system). All of my fish are feeding on pods throughout the day however I still have enough pods to feed a mandarin ontop of my 5 other pod eating fish in my 4’ tank.
If the OP does what I do then that 4’ tank can most likely house a mandarin and have it thrive. Also, if we’re saying smallish then wouldn’t that mean a 6’ tank won’t house a mandarin for longer than 6 months no matter how established the tank is?
I would avoid the Fox face (much too large), possibly avoid the Yellow tang. I would consider a Tomini tang instead and the lone tang in your tank. The color of the Tominy is beautiful, even if it is not as bright as the Yellow tang. I recommend adding a harem of Royal Gramma instead of just 1. A pair of fire fish. Don't add the 6 line wrasse or you will be sorry.
Why would you avoid the foxface? IME they don’t get over 7.5 inches (8 at a push) in captivity. I believe Jay did an experiment of what the max size of fish in captivity are and most of them stopped at around 80% of their maximum wild size.
As for the gramma harem, I personally wouldn’t advise this as they can be aggressive to their own species. If the OP got this trio as established adults then there would be a risk of getting 2 males to one female which would cause fighting.
A pair of firefish is another thing I wouldn’t do as this isn’t natural for them. Only one firefish species is communal and this is
Nemateleotris magnifica. The rest are usually found solo in the wild and not normally in pairs or groups.
The rest of it I agree with you on though. Spending money on a shrimp that may die if not large enough is a risk that probably isn’t worth it. Also I do agree with depending on which species of Halichoeres greatly depends on the order or introductions.
