I have emerald crabs, peppermint shrimp and blueleg hermits all in the same 75 gallon tank. Actually it has a CBS, cleaner shrimp and Halloween hermit as well. No issue amongst anyone. The emerald crab will occasionally posture towards the other inhabitants if the get too close during feeding time. Otherwise has never been been aggressive. One time I saw two of the emerald crabs fight each other but that was partly my fault. I was rearranging some rock and they both wanted to hide under the same rock.
One night in Bangkok and the worlds your oyster. The bars are temples but the pearls ain't free.