I don't have experience with crayfish, and Mbuna but...
I recently (mid March) received a bucket with vampire crayfish and Andinoacara cichlids (both caught together in the same river in Panama).
I put the 3 crustaceans in a 180 gal tank with about a dozen cichlids, a Pleco and a goby

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The Crayfish constantantly tried to grab the cichlids, but the Andinoacara easily shook them off.

More importantly the Crawdads were highly territorial and would fight whenever they met, to the point of tearing off limbs, and killing each other, in the 6 ft tank.
I saw them wandering around the tank until about a week ago.

They haven't been seen since, so whether or not they crawled out, killed each other in territorial disputes, or whether the cichlids ganged up and took them out in a concentrated, pack attack, I don't know.
There is a Crawdad lower mid left in the pic above
The tank is outside on the patio, so if they crawled out, they could easily disappear in leaf litter and been killed by the local fauna that live in the yard, everything from snakes, an feral cats, to large cane toads.

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