I understand the logic behind all the Chapel first arguments. But it seems also that you are kind of giving up your lucky 5/2 start if you do that. You open Mountebank (or Witch)/Chapel, your opponent opens Silver/Chapel. They colide, and you choose to play Chapel. Now, your turn 3 looks identical to your opponent's turn 3. And your turn 4 is going to be slightly worse than your opponent's turn 4, because perhaps he has a Silver turn 4. So he buys Mountebank/Witch turn 4, while you buy Silver probably. Now, you have identical decks, and you got absolutely no advantage out being lucky enough to get "the best opening."
Then again, I suppose that might just be how it is, and it's "the best opening" because they don't colide more than half the time.