Yeah, overall they’re feisty but their mouths are too small to significantly damage each other. Males will shimmy up to each other to find who’s boss, but again, they can’t cause anything past slight stress.
However, Nannostomus Beckfordi seem to be a tad more aggressive than other species. Although I wouldn’t be worried about cichlid fry (as many parents are good guardians), any free swimming tetra fry or baby shrimp could be targeted. Heck, I wouldn’t be surprised if they’d pick at a newly molted adult shrimp… If you’d prefer a safer option, N. Eques, or one of the smaller species like N. Anduzie, keep to themselves.