You say they prefer to be in groups bit is this a requirement for them? Or more of an option?
In groups do they form their own territories? Fights within the group or any of that?
I want to keep my tank peaceful for sure.
Most schooling fish would feel more secure in a group. For example if I kept my tiger barb by itself, it'll be timid and start its bad habit of fin nipping. But kept in a large group, it display its natural habits