Are you talking about changes in the fourth game? In the fifth game, troops no longer move without a hero, and the division into schools was already present in the third part. Heroes participate in battles starting with the fourth game; in the fifth game, their involvement in battles was slightly limited. And in the third game, the hero simply cast spells.
Демократия есть одурачивание народа при помощи народа ради блага народа.(Уайльд Оскар)