Heroes 5 – “A masterpiece or an unfinished product?”

So, in your opinion, which is the strongest faction? But please provide a justification, without using vague phrases like "it's obvious to everyone." And if you remember, in Heroes of Might and Magic III, Tower and Dungeon were the strongest. And in Heroes of Might and Magic IV, the Barbarian was the strongest hero, especially at level 20 or higher. 8)

P.S. This question is for Tigryonok.