Here's my question: What can I do to make their transition as good as possible and increase their chances for survival?
Here is what I have done: They are in a small iso setup right now--basically just a plastic tub with plastic wrap over the top to keep in humidity (with air vents, of course). It has forest bedding, fresh and salt water, appropriate temp and humidity ranges, and fresh food with calcium supplement available. Also new shells to change into.
Here is my experience: I have been keeping crabs for 8 years. My guys are healthy and happy. I'm pretty set in my routines, but it's been a while since I've added new crabs to the setup, so I just want to make sure I give them the best start possible.
Do you have a routine you follow when you buy new crabs, especially if you don't know about their previous setup or health?
One guy dug down immediately, and the other 3 are just hanging out. They have visited the food dish and saltwater dish, but mostly they're staying put.

Thanks!