So what's the deck that you have most wins per hour with? I can't exceed 6wph with any deck. Hearthcrawler used to do 11wph easily with most decks, but I guess that was becasue of the fast mode. Post your score, deck and routine if used other than default.
Games usually last 5min + anways, even if your opponent is slow, with auto concede on (at rank 20) you can get 6-8 with some zerg decks, but in the current meta it'll be close to impossible to achieve 11 or more.