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

Seriously, it's silly to judge the strength of Haven (or any other faction) by playing against the computer or completing a campaign (even on Hero difficulty)... For example, if Deleb shows up with his ballista at the end of the first week, while your army consists only of peasants, archers, and swordsmen...