In my experience (I keep 8 so they school more, but...) yes, this is normal, they should be fine, they do best in schools, and can get stressed out with out a school, I think that’s what lead to my first rbp to die, I had him alone, they are very skittish fish, and they dart around (and follow each other around) the tank a lot, atleast as juveniles, hope this helps, if you have any other questions I’m more than happy to help you out with anything I can!😁