You've room to up the numbers of the tetras then, which is a good idea.
Clown loaches do better in larger groups but as they get so large your tank might not be suitable for them long term. If they're tiny now, they will grow, so bear that in mind.
The shark could get a bit territorial, again something to bear in mind as it gets larger.
Can you describe the fish you don't know the names of? Anything they look similar to?