I find you can do slow deck against mage and shaman, if you have Mutanus. you have to play in a very specific pattern that they end up dealing with what/how you play and finish quest with not enough mana left over to play it. After eating their quest reward they still have a chance, but it is not as horrible for you.
I always concede against warlock and mages, yeah, you can get maybe a 5% winrate but the suffering is not worth it and I had a very incredible winrate with my deck according o decktracker… then I noticed… I had “Don’t register 0 turn games” on and the decktracker didn’t count all those concedes. After I put that off I had like 40% winrate and still it felt way too bad to play.