Walkthroughs for custom maps.

Anatoly43, it seems like you have the Spirit of Despair in your inventory; you can use it to prevent the appearance of unfavorable enemy morale. As for the catapult, it depends on luck. Very often, our main enemy when attacking a castle is our own catapult, and the power of the meteor shower isn't always enough to destroy it on the first try. Or, as in this case, it's a battle without magic.

Added 13 minutes later
Anatoly43, you can make the losses even smaller by collecting the Cursed Armor; individual pieces can be found with different heroes (at first glance, not all of them, though). We'll suffer a significant stat decrease, but the mass slow and curse should outweigh that in this case.