Balance in Heroes 5.

The developers constantly adjust the balance in patches. Before version 2.1, Humans and Necropolis were clearly the strongest factions. In 2.1, training and necromancy were limited. After that, they decided that they had limited them too much. In patch 1.5, these factions were strengthened compared to 2.1. Exception: in 2.1, Necropolis is stronger than in 1.5 if they have several native castles and a lot of sulfur. But even then, not immediately.

So, there is a huge difference between the balance in version 1.0 and the balance in the latest versions.