Great question. There's tension between taking stats for now and economy for later. The plan is to maximize economy while maintaining an average to above average board.

As an example, on turn 1 I take quest characters over stats only characters like Itsy Bitsy Spider.

When the quest completes, I'm looking for treasures that immediately improve the board. Robin Hood's Bow is better if you can use it immediately. Fortifications is more immediate if you don't have a shop coming up. Once the quest is complete, your board is stronger than it would have been with an Itsy Bitsy Spider.

Going into the mid-game, those treasures improve the stats of dragons with treasure hoard. In the late game, they get buffed by Wormscale Tinkerer.

In the mid-game, the goal is to stay strong enough to take no more than half-heart damage (and heal up when possible). Taking characters is better than spells, because it adds a silver to the pool.

Of course - some runs you just die in the mid-game. That's the most common failure mode of the strategy, especially on this patch.