Sorry, I thought you may have seen previous posts by myself about the Mandarin.... ooops, sorry.
The mandarin is being successfully bred in captivity now, and it may be possible to find tank-raised Mandarin gobies that have a broader diet.
If you can find a tank-bred mandarin, then I guess that would be ok.
If they are wild-caught, I would urge you to re-consider. My LFS had a wild-caught mandarin that they refused to sell to anyone. Eventually, after about 3 months, a 'professional reefer' purchased it from them.
Okey-day. Yeah, I was thinking on sticking with captive-breds as opposed to wilds. I'm well aware of how bad things are getting out there.
Hmm. May have to pick just one of those angels, then...or get a very very big tank. Sounds like fun. Any thoughts on what might go with them? How about the harlequin tusk fish? Maybe some pajama cardinals... or a fairy wrasse...lol. Lot to think about, and I know very little about saltwater species.
I do think the flame fairy wrasse is supposed to be nice, right? So maybe I could trade out the flame angel for the flame wrasse.
Many Saltwater fish can be mixed quite safely (always check first though). It's mixing conspecifics and same family that can get dicey.
Two Coral Beauties - not a great mix
Two Angels - not a great mix.
Two gobies - not a great mix.
Two conspecific Clowns - not a great idea, UNLESS you get a known pair, or at least get one bigger than the other.
Two species of Clowns - caution needed, recommend a large tank. Tangs - need very large tanks to house multiples.
Most Cardinals can safely be stocked in multiples (3 or more) - The PJ's, Bengaii, three stripe can all be mixed together. Damsels/Chromis can be kept in schools.
You also want to avoid keeping Trigger fish, Eels, Groupers, Lionfish in a community tank. They are generally predatory fish, and may devour your stock.
Then, the last piece of the puzzle, what do they eat? While they might mix with other fish just fine, they may have an appetite for inverts (e.g. Flamehawks) or Corals (many angels have an appetite for SPS/LPS corals)
I did 10 yrs of research and I am still learning lol. Here is my stock mixed pair of clowns, firefish, watcher goby, flame angel, LTA(long tentacle anemone), coral shrimp, sexy shrimp, peppermint shrimp, peacock shrimp(trying to catch the little one), tang(rehoming to Taleigh's tank once it is cycled), emerald crab, and tons of coepods lol.