Sorry but it will be impossible for the Yankees to win with waiver wire pickups and cast offs. You need steady pitching as there is simply no way that you can outslug everyone all of the time. That was the old Red Sox formula back in the late seventies and early eighties.
Be very afraid of Oakland. Their pitching is excellent, they have young and hungry guys without the injury or ego problems of older and start studded teams. I think if they were to make it to the series it would be a good one.