OOOOOOOH MAN!!!!!! That's horrible!!! Wow! Thanks for sharing the pics, I might not have believed it if there wasn't pictures! I don't want that to happen to my plecos!
Whenever mixing any fish with pbass research max size also importantly growth rate.. If a fish gets 2ft but grows 3" a year then it might not work. If it can keep up with cichla growth rate, is already a good size then you may have something that works.
Not all large cichla are predatory towards fish of decent size. How often you feed, what you feed, and individual fish behaviour will matter. At the same time general rule is big fish eat small fish so be prepared.