In your opinion, which faction is the strongest in Heroes 5? Let's discuss the advantages and disadvantages of each faction.

So, after the introduction of dark energy, necromancy became very weak in the late game, so both races' units are bought for shiny coins. Additional castles for the Necropolis are not a problem on a large map. The army itself is stronger than the Necropolis army, especially the cavalry under Axel. So, humans have an advantage in a prolonged game. Of course, randomness and skill still play a role. But yes, the size of the map is a major factor.