found two crabs but?

[Griffin]

Found a red eyed grey crab with solid claws and he was removed ( i was trying to be nice to put in sump but ended up with pieces of food ). Next night i found another crab in the same hole and another one lower down. One is hairy on top shell and greyish and one is hairy on the legs only but grey smooth shell. The thing i did notice is that they both have the same claws as my emerald crabs (looks like little cups at the end and open in the middle). I will try and get a pic, i kinda figure they might be safe but wondered if anyone has had anything like the described. They both seem to eat just off the rocks as the emeralds do but the decision is out to the jury to see if they should be evicted without notice to the sump. The claws make me wonder
Brad - you have a soft spot for crabs - what do you think

Cheers
Rich