Okay, fair point. It is indeed important to start from simple cases. I guess I didn't say what I really meant there.

My real concern is this: posters are trying to develop the limits of e.g. anthropic reasoning. Anthropic reasoning takes the form of, "I observe that I exist. Therefore, it follows that..."

But then to attack that problem, they posit scenarios of a completely different form: "I have been fed solid evidence from elsewhere that {x, y, and z} and then placed in {specific scenario}. Then I observe E. What should I infer?"

That does not generalize to anthropic reasoning: it's just reasoning from arbitrarily selected premises.