"C. oblongus" is an outdated name for "C. siamensis" and I just went with what was in my brain instead of really checking. 
I have one, love it, but I've never had success with more than one or less than a small school. 
Common names annoy me, but yeah real SAE's won't do the sort of damage Flying Foxes will. 
I once had to chase down a Betta with a Ghost Shrimp taking a ride and chewing a hole in its tailfin. Possible that once something started the damage other fish joined in on the feast. Something smells blood in the water and thinks "EASY FOOD!"