This is from The Aquatic Community:
Cherry barb setup:
The recommended minimum aquarium size is 75 litres (20 gallons). The Cherry barbs should always be kept in groups of at least five individuals, preferably more, since this is a schooling species. A Cherry barb that is kept alone can become very stressed in the aquarium.
Try to mimic the shaded and densely grown habitat that wild Cherry barbs live in when you set up your aquarium. Preferably choose some plants that will grow up and cover the surface.
A clear area for swimming should also be included. Comparatively sturdy plants are recommended since the Cherry barbs will nibble on them. They will also eat algae.
Good filtration and a quite a strong current are recommended. Cherry barbs live in slow flowing waters in the wild.
Cherry barb tank mates:
The Cherry barb is a peaceful fish ideal for a community aquarium with other non-aggressive fish species that appreciate the same type of environment. It is naturally important not to house Cherry barbs with predatory species that will consider them prey. As mentioned above, a Cherry barb should always be kept together with at least 4 members of its own species. A school of Cherry barbs can be house with a wide range of docile fish species, such as Danios, Plecos, Bettas, Corydoras and Rainbow fish. Nippy fish species like the Tiger Barb should generally be avoided.
Cherry barb behaviour:
Cherry barbs should always be kept in groups, but they will not form really tight schools. Within the Cherry barb shoal, a strict hierarchy will be observed. If you keep more than one male, the males will compete with each other but rarely cause severe injury. Keeping two males in the same aquarium is actually highly entertaining since the males will “dance” in front of each other rather than simply fight. During the dance, the males will encircle each other whole displaying erect fins. Males will also become more vividly coloured when kept together with other males.
The Cherry barbs are considered to be a middle-tank species, but they will often venture close to the bottom as well as swim up to the surface in the aquarium, especially if the surface is covered in bushy plants.
That would explain why there are differing opinions on whether they are a schooling fish or not. They don't form tightly knit schools.................it also appears it would be okay to keep males together although it doesn't say keeping only males is okay.