Slowly Dying(?) Emerald Crab

[PiSoup]

Hi y'all. I'm a relative newcomer to reefing, so this might be a pretty ordinary situation.
One of my emerald crabs appears to have potentially gotten into a scrape with something else in the tank in the past few days. He's down to 4-ish legs and one claw and is having a lot of trouble moving around. He's on the small size and hasn't grown much since being added to the tank a few months ago; the other crab that was added at the same time and who was about the same size then is now about twice his size. I suspect that the coral banded shrimp or one of the larger hermits might have gotten him.
Water parameters look good to me; no nitrates/nitrites/ammonia, SG: 1.025, temp: 77.5F, Ph: 8.1.
Is this the circle of life? Should I "put him down"?
I just feel bad that there's a suffering member of the tank right now

 

[WVNed]

It is possible that he will get some of his legs back the next time he molts and all of them eventually.
I have a crab that only had 2 large legs left. Now he has all eight but they are small. I would suspect the larger crab to be the suspect. When they are hungry the largest one eats the appendages of the smaller ones. It seems to be a survival strategy.

 

[PiSoup]

I'll keep my fingers crossed that he manages to make to his next molt!