Haven vs. Fortress (how to play against dwarves?!)

Let's bet that I can level up so much that even 100 Combat Damage won't kill a level 1 Dwarf with the first hit?

Well, if you take the red warriors and the dragons fly from a distance, then I can imagine such a scenario.
A specialist in "warriors" might have more than 20 hit points for one warrior + 2 from the skill for defense + 4 from two rings of life... and considering, for example, a column that increases the number of hit points before the battle, and the unlimited level of the hero, it is quite possible to have 40-50 hit points for a warrior with huge defense -30 damage from the skill and, for example, from "Stalwart Defense". By the way, the hero can cast the maximum upgraded Celestial Armor (the one from Nature Magic) and Stone Skin (from the Dwarven set).
And the dragons' attack from a distance of 9+ cells, with an attack that negates counter-attacks.

It's a different matter if the dragon first flies close to the warriors and then attacks "without a penalty from distance" - then it's not certain. although it needs to be tested!