I've had leopard danios for a while now and really enjoy them. And, I'd imagine that white clouds act very similarly. I, personally, wouldn't call them a schooling fish. They are very active and like chasing each other around, so maybe in that sense they are somewhat grouped. But, it that considered a school?
46g bf, XP3 w/ vertical spray bar, CO2 w/ SMS122 & diffuser,100% Flourite, 96w+55w cf AHS, AGA Member