you want to kill aggro dead, all aggro for all time hunh.
Oh noes, Aggro decks will have to use their minions to go through taunts or *gasp* use a spell on a taunt.
Don't stats become less relevant the more expensive the creature is? There's a huge difference between 2/3 and 3/2 2-drops, and almost all the viable 1-drops are 2-attack, but outside of patron how many decks have minions that aren't either part of the win condition or chosen because they can immediately affect the board state? Would you play MC if it was a 4/4? Would you play Boom if it was a 7/5? Loatheb if it was a 4/5? Antonidas if it was a 5/5?
Stats are extremely important up until the 4-5 mana. Beyond 6 and up stats are enough by themselves.
Zombie Chow still gets run and it's a stats monster. If there was a 2 mana equivalent of Zombie Chow (3/4 gives the opponent 7 health) then it would be run no question about it. Hell Totem Golem has become the staple 2 drop of Shaman despite having a considerable draw back. Minibot is a stat monster and is a staple card. Muster for Battle is a 4 stat value card for 3 mana, obviously it's run. Shredder is a stat monster on average, of course it's the most used.
It gets tricky at the 5 mana. There aren't huge value monsters at 5 mana. Loatheb is used for the effect, I would say that even if it was a 4/5 it would still get used though it would get used A LOT less if it was a 5/4 (because of Shredder). Belcher is also a stat monster and hence it's the default 5 drop in quite a few decks. Fel Reaver is used in SUPER aggressive decks and it's the best stat for stat 5 cost in the game (but comes with a considerable drawback).
6 mana and up, you need a godly effect... stats aren't enough. People used to run Sky Golem/Cairne in that slot because these cards are amazing raw stats for the cost but that's too slow and low board impact these days for the cost. The only other card that is run for pure stats is Highmane though it has the Beast tag so Hunter gets the added synergy. Notice that these cards just like Shredder have powerful deathrattle effects which means that they maintain their stats for quite some time.
Asides from these powerful deathrattle minions, the other 6 mana cards have powerful effects. MC, Cabal, Sylvanas, Emperor Thaurissan. That's because 6 mana is the slot where powerful legendaries start coming in as well.
Above 6 mana it's all about powerful legendaries. I can't really think of any non Legendaries minions that are used past 7 mana.
Boom would get played at 7/5, MC would get played at 4/4 and Antonidas would get played at 5/5 but all these cards would be quite a bit weaker.