This is an interesting topic because it addresses the concept of "warm-up" holes.
I wonder if that concept is a contempory one, or did the ODG architects design with that concept in mind too?
I doubt that Travis would have designed the opening hole as a warm-up because he was such a great match-play player, and he carried some serious game-face with him on those opening holes. He wanted to get up on his opponent early in the match, and so I think we may assume that at least he would have designed for difficulty and not "warming-up" in the first hole.
Maybe the reason why so many opening holes are fairly benign is because they almost always play down hill, owing to their proximity to the clubhouse, which naturally occupies the high ground?