Guys, I don't know if I'm the best one to explain something like this, but I'll give it a shot.
There's no "mix/maxing" in Dungeon World. The raw strenght of a character isn't his damage output or his HPs. When you choose your advanced moves, you're just deciding in what field you want to play and be heroic, but they are all at the same level. So even when a party with very low damage output faces The Apocalypse Dragon, it just means that they are going to bring him down with different methods than stabbing him to death. Maybe the Fighter can ask his heirloom weapon how to defeat the monster once and for all. Or the Wizard could make a ritual to enchant a dragonslaying spear. A Paladin isn't strong because of his damage, he is strong because I Am The Law and Quest are wonderful, versatile moves. Even just a well placed Spout Lore can do the trick. Monsters are not just sacks of HPs waiting to be emptied. They are an all around challenge created by the GM, but are the players, using their characters as vehicles, the ones who invent a solution. When creating monsters and converting an adventure, just stick to the rules and everything will go fine!
When in my previous post I reported some monsters stats I didn't do it because characters are actually going to damage out every monster; quite the contrary! Indeed, the best tactic against a dragon surely isn't charge it and hope to kill it before it kills you!
It's already been said: everyone should read
this post before playing and thinking about monsters.
I never balance monsters to the current party I'm GMing. It's a problem of the players to defeat them, it's their contribution to the story to find an heroic way to do it! :D My duty is to make monsters 1) live 2) fantasy 3) faithful to what they are in the setting, following the rules DW provides. Luckily, not only DW has plenty of space for a player to be creative, but it actually drives the players to invent and create! So it's not a matter of "oh god now I have to come out with something both creative and powerful". It's just, "what's the most obvious thing my character would do in this situation? Ok, let's see if it works!" And usually this works like magic because chances are, what you believe being the most obvious thing your character would do, it's actually a creative and useful thing to build the story!
Ok, maybe I ranted a bit, but I had a point. Somewhere.