did someone noticed the bug? Let's say it's turn 7 and you have Tracking in your hand and you want to draw Kathrena Winterwisp. As card options you can draw her and 2 big beasts. Of course you pic her. If you play her on turn 8, she doesn't recruit a beast and the deathrattle isn't working because the beasts are no more in your deck.
That means you can't have trackig, KW and beasts in you deck, because it destroys the beasts if you don't pick em.
I only run one in my Kathrena deck. It's best used to look for an immediate answer or to get extra damage for lethal. It's not a card you play just because you have mana left. It's definitely not card draw since you spent a card playing it, so don't think of it that way. It's a way to fish for stuff you need right now but haven't drawn yet.
EDIT: It basically triples your odds of getting an "out" if you need one right away.