You could grow out an arapaima in there for a little while... Point is unless you have long term arrangements you can easily end up having to rehome the fish or potentially stunt their growth. That foot print will give you some breathing space but your going to want another couple of feet length and width for long term health.
All the fish I stock in the 5x3x2 will definitely go in a bigger tank!
Right now the 5x3 is the best I can do for my living room since my basement won't work for a 8x3 as of now
The fish you've listed will all last quite a while if picked up at the juvie/pup stage, but within a year you'll wonder why the tank became so small. I won't bash you, a year is a long time to make things right. Even an 8x3 might not seem so big in in a couple of years for the rays.