Part of the problem with any schooling species is that they school for protection. It doesn't take long for them to learn that the tank is safe, and that schooling is required.
Also, many fish that are captive bred (including neons) is that the gene for schooling doesn'tdictate successful breeding. In the wild, fish that don't school well tend to be eaten more often, meaning they contribute less to the dominant behaviors of the fish. In captivity, this isn't the case, meaning more fish that don't school tightly can successfully breed.
And finally, tank size and the number of fish in there is important. In a 10, there simply isn't enough space for the schooling behavior to really be noticable. In a 55, it's noticable if you have a large enough school.
The best schooling behavior I've seen, given all these variable, had been in the pygmy cories. They really are more mid-water fish than the 'regular' size cories, and they school very well, even in smaller groups of 6-8 fish.