i know of someone with a big 20" wykii in comm tank and its fine, so i tried a smallish 9" in with my mixed com fish ranging from 6" to 15" and it was mental moved all the fish round the tank nothing would stand up to it, had to take it out after 10 mins i sure it would have done some serious damage. ive also had a simaler sized asian red tail in the same tank, and it was aggresive but only to other ctafish. I once thought about keeping the two together but its definately not possible, my wykii is fearless. if your thinking of keeping either in a comm you would need to grow them on with tankmates as small as pos, tankmates that can look after themselves large cichlids would be best, nothing too expensive, but be prepared for disaster