I hear you, it doesn't take the circumstances into account. Tom Landry not only started with the Cowboys as an expansion team, they didn't even get to participate in the draft prior to their first season. Some HC's took over winning franchises. And, yes, I'm talking about Madden who took over the team in 1969. The year before they were 12-2 and the year before that they were 13-1.
When I titled it "Top Head Coaches" I didn't mean to imply they were the best and ranked accordingly. I just couldn't figure out a title that referred to the winning percentage so I included the information in the opening sentence. With that said, it is still a pretty impressive group and it is reassuring to see McCarthy's name in that group.
Under any circumstances, you want to win, that is what HC's are held accountable for, fair or not.