So this is a deck mostly there to take advantage of rats of extraordinary size but also having lots of minions on board. So the plan is to plan on how to get as many rats as possible out of each one. For that you have the sleepy minions taking up boardspace so its important planning ahead to have as many spaces filled as possible going into the rat turn. Don't get too greedy with the traveling merchant though. Even if it can be a bigger giant it's probably fine as a 4/5 but try going for a bit bigger than that. 

Some dormants are flexible in how long they stay so try to plan ahead. There are also cheap spells and minions if you go over 6 mana. Wrangler will always find rat king too who is the greatest at taking up space. When you have gotten rats in your hand you can get some refill from saddlemaster with the rats costing 1. Broom comes in doing overtime too as the minions are quite slow and gets some help from trueaim cresent in fighting for board. 

The carrion studies can be used either for discounting cheap minions for your rat turn or getting your king out early. And best hit is always more rat kings. Probably. 

For winning the game though... You may have to cheese a win out. Gl.