I have a Falco added from a friends tank that he had to break down. In for 3 weeks now and no issues. However, he is in a 210g with mostly mature fish. He keeps to his own and holds his own since my others like to pick on newbies. I also have a lawnmower blenny from same person and is doing great. My tang takes offense to him, but expected that since they eat similar stuff. My tang did that with my old lawnmower too.
The Falco was a great addition. He is fun to find and watch move about. I do not have any shrimp though. My large christmas wrasse takes care of those. At least the peppermint. The blood red I had died after having him over 6 years. Great shrimp!