HLF

I was just wondering how effective (or if effective at all) would those small bait stealers be as bait for larger fishes. Often, I hook up cardinals, glass fishes, tripods etc, throwing them back without giving them a thought. Is it worth any time trying to hook them up and using them as bait?

I personally don't like using them because these fishes usually have hard body which I don't think predatory fish find appealing. I ever witness an angler landing a 1kg or so grouper on glass perchlets, and a cobia on whiptail bream. So if you're specifically targeting for groupers, it might not be such a bad bait.

They are also dangerous to handle as they usually are covered with thorns

What we would consider non pest would be like kembong, selar, tamban and whiting
For other fish usually the hard bodied fishes aren't so effective, go for baits like gelama and even chocolate hind. At kelongs, groupers usually aren't too picky and most baits will do. I put a palm size gelama in the keep net with 1kg plus groupers and when I woke up it was in the mouth of the grouper.
While the common rule is to avoid hard bodied fish like tripod and leather jacket, I've caught small groupers with glass like fish in the mouths, not sure if it was a species of ikan billis or a glass perchlet though.
Other fish like bream and baby snappers can be effective too, soft bodied fish are more preferable maybe also because they are easier to eat

Sorry not ikan billis or glass fish they were silver sides. Silver sides seem to be good baits for smaller fish like groupers. The smaller groupers seem to hit these fish because they are small enough compared to normal tambans