First and foremost, this is a control deck. Even though it has powerful swing cards in here like Dragonqueen Alexstrasza, Galakrond, Azeroth's End, and Electra Stormsurge + Dragon's Pack combo. With that in mind, we need to conserve our resources when playing. Always try to make your opponent over extend and play that one or two extra minions before clearing with Hagatha's Scheme or Earthquake. We can take a few hits because there is quite a bit of healing and armor gain from our hero cards (and Hagatha, the Witch can give us more healing).
Now, you may be asking, "Why 2 hero cards? Don't the hero powers overlap each other?" and yes they do. HOWEVER, both hero powers are extremely good and way better than summoning a totem so even if you have to overwrite one with the other, you're still better off than you were before. Both hero cards also have great battlecries to swing the game and control the board, and can be recast again with Shudderwock. Against slower matchups, i'll always try to Galakrond first, then Hagatha because Hagatha's value is better in longer matchups.
*side note* - Don't be afraid of using a tier 1 Galakrond, or tier 2 if that's your best play. Because there's only 4 invoke cards in the deck you'll rarely get a fully upgraded Galakrond. Most of the time, I'm fully content with 4/4's.