No one is listing the diets they're attempting.
These species would do well with mixed feedings of bloodworms, blackworms, scuds, ghost shrimp, chopped earthworms (or whole if they're large enough), guppies, troutworms, tadpoles, mayfly larvae, crayfish, etc. Anything meaty that they can hunt will provide a good diet for them. These are not the fastest feeders so, ensuring they receive their fair share would be a big step in beefing them up in a comm tank. Feeding them with the lights off will improve their foraging instincts.