The clown loaches will far outgrow the tank eventually. If the unidentified fish are common plecos or something similar, they could get even bigger.
Other than those, you're fine. If the two bottom feeders are smaller plecs like bristlenose or bulldog, they'll be fine, too, and most species of loach won't get nearly as big as the clowns if they're loaches. If they're corydoras, they'll prefer a larger group, and if they're any other catfish, all bets are off since they could get anywhere from two inches to four feet long. Do you have a picture or something to help identify them? As long as they're a wildcard, its hard to guess how they fit in current and future stocking.