Tom K, I think it is the opposite.
Picture this: if a club is too upright for you, the toe will be too high off the ground. If toe is too high off ground, it will pass the turf and not dig.
Conversely, if a club is too flat for you, the toe is pointed down too far for you. Because the toe is lower than it should be, it will then dig into the ground, causing face to open, and shots to go right.
That was my understanding; I stand to be corrected.
Tom