Not to be pessimistic, but maybe see how long you can keep one alive. (I have had two—not at the same time— and was not able to keep them living long.) Best wishes.
I agree it can be hard to keep meat eating crabs alive unless you either feed with a shovel or target feed. The first option is not recommended on a tank that is experiencing an outbreak of a certain pest as the food is what is allowing them to get ooc. There are many other ways to get them under control which don't require going overboard on predators. A long pair of tongs for example.