I can only think of two that would be brutal.
I had 2 Gouramis and then 2 Albino Cories sucked into my Whisper 20 (I couldn't fine the strainer tube for it). The Cories made it all the way through to the bigger cartridge area and survived. This was in December, and they're in my 55 schooling about!
In my 55, I have 12 Cardinal Tetras and then two female Bolivian Rams mixed in with 6 white clouds, 1 Rubberlip Pleco, 3 Raphaels, 7 Yo-Yo Loaches, 2 Otos, and 2 Peppered Cories (Don't worry, I have 2 XP3s, 1 Aqueon 55, 2217, and an 80 gallon sponge filter, along with a ton of plants).
The Tetras are all missing their left eye. No nipping going on, just the left eye missing on each one of them. I'm assuming it's the Rams, but it could be the Loaches.