Here are some better shots of the largest crab which we are trying to ID. He is at least 2x bigger than the other 3. The red crab hardly shows herself. She's dug a nice hole under the live rock and pops out every so often.
Here are pics of all 5. The last pic is the bigger one obviously.
What I think you need to do is get all of the crabs out of that tank as IMO they are all carnivores and will just do more damage as they get larger and grab fish or corals during the night which is when they are often more active.
I do not think any of them are safe for your tank ... and I do not see a true Emerald crab ... they are way larger than what they should be. The red one I cannot ID because I cannot see it very well but the usual recommendation when one is not sure is : remove it ...
And on that last one : that is NOT a M. sculpts for sure, claws are way too large.
Here is a pic of one that I have (and that is 1 in a 20 gallon tank) and it is about 1 inch across ... and the claws are very small
Whatever that Pet Store sold you are not what you want