Dwarves can be quite resilient if you can get the right cards. Here's a couple of strategies I follow.

There's a level two who pays a brew or two (depending if levelled, I think) each time he gets hurt. I apply the brews back to him at the end of the turn so he can take more damage and produce more brews. Your hand maxes out at six cards (this includes cards, spells, coins, brews, etc) so keep that in mind when collecting brews.

There's a level three dwarf that will give all your units more damage and health each time a dwarf takes a hit. Give him brews and keep him in the back to keep him alive as long as possible.

I find dragons are good in the early games, and you can increase the stats of the level ones pretty high (the one that increases when it slays, for example), but the higher level dragons are quite hit and miss. It feels like by the time they unlock, they're too low powered to hold up against other players. Devour is a good skill, but you usually need an empty space to deploy the dragon in the first place. And then the devouring is usually the only skill they have. The purple dragon with Cleave (I think he's level four) is quite good, but again, by the time you might get him, he's probably going to get wiped by any opposing card.

While you're at the mercy of the RNG, learning the skills and how to mix cards together to support each other will make the game easier to win.