I'm surprised that no one mentioned Krag. In my opinion, he's great on both large and small maps. To maximize his abilities, it's enough to take Stunning Blow, Devil's Blow, Self-Help, and Empathy. This set of skills is ideally achievable at level 10, and then... Neutrals don't even have time to react because he hits them right at the beginning of the battle, pushing them back on the scale. As you know, like the Orcs' "We Rush into Battle," if you put 6 level 1 Goblins, their high morale moves the hero along the scale like a rocket. If the battle is prolonged, use Support on the archers (another extra attack). And the attacks are devastating; no magic is needed. At level 20, this is a double attack at worst, and if the 30% chance of a double attack triggers, it's a fourfold damage. Taking Utopia without losses is not a problem because Krag easily and effortlessly takes down 4 dragons per attack. If you also like ballistas, they will take out low-level creatures, and the hero will take out the monsters. If you don't like ballistas, Krag doesn't have the Machine Mastery skill initially, so you can level up something else. That's what I said.