confused, hermit crab molting issues ?

[crownedhorde]

hello! i'm new to this forum and to hermit crab care. recently, about a month or two ago, we got three hermit crabs. at the moment they have a 10 (?) gallon tank, with several inches deep- at least, 5 or 6, substrate, consists of flukers hermit crab sand, cocofiber. they have plenty of twine and branches to climb on, as well as a hide, and 2 water dishes (salt and fresh, both are treated) along with a food bowl. i often feed them fruits, shrimp, and their assigned hermit food every so often. their humidity and temperature are often as they should be for hermits, me and my brother often come by the tank to mist it to maintain the humidity.
Now, i'm not really? worried, on how inactive they are, since i've expected it. they are new, after all. their tank is quite small as well- which i discussed with my brother that we would get a new, bigger tank- but once one of our crabs (named Stinker, to clarify,) finished molting, as he decided it would be funny to do so right when we were planning to.
That was around a month and a half ago- and now it seems hes come out, albeit in exchange for one of the other hermits (Cute, the smallest,) we've got in the tank. But Stinker came out looking a little rough- on the shell side at least, but also in the notion that, he was missing one of the last portions on one of his legs- and i'm worried. My brother saw him out this morning, and we're assuming maybe they switched places in the night. But the missing leg has me a bit paranoid. Maybe Cute drove him out from underground? It seems odd enough, but i doubt it would be the bigger out of the lot of them. Hes not a very active fellow and is often in the hide, save for at night which is expected.
I noticed this around 30 minutes ago and it has me worried. Some clarification to what might be going on would be amazing.. i tend to overthink and really don't want my little guys just duking it out when i'm not looking.

[curlysister]

What are your current temperature and humidity readings?
Do you have a lid on your tank?
How big are your crabs? You are correct that you will need a larger tank sooner rather than later. Overcrowding can cause crabs to come across other crabs while they are underground.
Be careful with misting - you don't want to accidentally cause a flood.
Commercial foods often contain preservatives that are not safe long term.