Hi! As others have said, the fish/gallon rule really isn’t a thing anymore. I like looking at the bioload all the fish use. Like if I had a 60 gallon tank, I could fit 10 maybe even 13 low-medium waster fish (chromis, pj cardinals, blennies, gobies, etc) but I would only put 1 snowflake eel and a fox face or something in the same space because frankly, eels are nasty (albeit very very cool) and create a lot of bioload.
It’s also important to look at how your fish behave. I wouldn’t want 5 ‘active swimmers’ like dwarf angels, wrasses, etc in a 30 gallon tank, they would run into each other all the time. Better to have a swimming fish, one perching fish, a bottom dwelling fish, and a pair of clowns that just hang out in their host coral. This way even though you have a lot of fish, they don’t really encounter each other. A good example of this is a 30 gallon tank with a cherub angel, a longnose hawk, a goby/shrimp pair, and a pair of clowns. The angel swims around the tank, the hawk perches on the rocks, the goby stays in the sand, and the clowns don’t stray far from their host. This was everybody has plenty of space.
with your tank, since you have 3 low waste fish and you want to add 2 more low waste fish, I’d say it’s okay. The clowns should pick a host and stay there, the bicolor lives on the bottom, and the PJ cardinals are technically ‘free swimming fish’ but mostly they just hang out in the water column. I don’t think you should have a problem.