The larger the number of fish and the more room, the more you will see schooling behavior. The rest of the time, you will see shoaling. That is where they are all sort of near each other, but not doing much. I have 9 white clouds in a 50 gal
and they shoal, same with my silver tip tetras and serpaw tetras in the same tank. The fish that comes the closest to schooling for me are Celebes Rainbows. I have 11 in a 29 gal
and they are the only upper water dwellers.