Danios and White Clouds
The smaller types of Danio are rather similar to the various species of the genus Tanichthys although genetic studies suggest they are not as closely related as once believed.
The smaller Danio species like the Zebra Danio, the Leopard Danio and the Spotted Danio can be kept in a suitable sized aquarium with either the White Cloud Mountain Minnow or the Cardinal Minnow or any of the less common species in the Tanichthys genus. The Danios are faster swimmers and more boisterous so I suggest that at least six fish of each species be kept so they can form discreet schools of each species.
The larger Danios like the Queen Danio might be too big to keep with White Clouds or related fish.