Deck synergy is way more important than just "big cards". I have two cards that cost more than 4 mana in my Hunter deck. 50% of the time I don't even play those cards. I eve just swapped out Maexxna which is a 6 mana legendary for Angry Chicken, a 1 mana rare. Still feeling it out, but I needed more, early beasts.
How do you make sure you don't just run out of cards with that many cheap cards? I find by the end of the game where I can play 3 cards a turn I end up with just one in my hand, and I'm dead.
Buzzard is a key card for that. Every beast you summon, you draw a card. A few ways to play it is, if you do it mid game you can actually find yourself some lucky draws. It's been a few times I've played a buzzard, then played a beast, drew a beast, played that beast, drew another beast. Really susceptible to board wipes.
Another good play is early Buzzard with Snake Trap. If the opponent uses a removal spell, or polymorph, then doesn't really matter. That's actually a waste of that spell.
Ideally you'll have them just attack the buzzard, which will summon 3 snakes, draw 3 cards.
Anyone with any skill will remove the buzzard as fast as they can, otherwise you'll just drown them in minions. So usually I'll play one early to get them to burn a removal spell. And if they just ignore it? Release The Hounds!
Yeah, see, that's the problem. All of those cards you mentioned I don't own. In your first post you were talking about "big cards" - whether or not I (I know you were talking to the OP but it applies to me too) own big cards is not important when the deck synergy you're talking about isn't even possible with the cards I own!
Then you gotta find a way to make the cards you do own work together. That's the point. I'm not suggesting you use my deck (hell, I'm lucky to break rank 10) but I am suggesting you should focus on what you have, and how to maximize how the cards work together.
Know what happened last time I faced Deathwing? A legendary 12/12 dragon that destroys all of the other minions on the board and makes the person who played it discard their hand? I played freezing trap. He attacked, he gets sent back to the owners hand and now costs 12 mana to play. Which means it can't be played again.
This morning I played against a guy who dropped three Legendary in one match. First one I used a removal spell. Second one I buffed a Murloc to kill. Third one, didn't matter cause match was over. So he's taking whole turns to dump one card, that I'm killing off with just a small part of my turn.
Any hero has a way to deal with a giant, damaging, minion. Whether it's Execute, Polymorph, Transform... The question is of "better" cards. And big (lots of damage, lots of mana) isn't necessarily better. I have plenty of Legendary cards that I never play, because it doesn't fit how I like to play.
So look through your deck. If you have a lot of Divine Shields, maybe take them and a Blood Knight. Or if you have some Murlocs, build a lot of those (you can actually make a competative deck with just Murlocs, although you'll really want to have one of each, so you'll have to craft a little). When I get a daily challenge for a hero I don't play? I just make an all Murloc deck with their spells. Doesn't matter, Paladin or Warrior. Druid. Those cards work together fine. They buff each other. And I can steal a game or two, get my gold, and go back to my Hunter deck.