Rainbow wolves are smaller, apparently they usually only grow to about 8 inches.
And although they are not meant to be as aggressive as an adult hoplias, I think they are more aggressive than a similar sized hoplias.
If you only have 4 fish in your 110 with hiding places it might be oke, but I think the ery ery would be capable of killing those other fish without much problem unless they are much bigger.
How big are they?
A jag is pretty tough right? And a paroon shark is quite fast and also look quite tough.
If the ery ery decides to kill I'd imagine the knife would be the first to go.