Can you explain why you think that there is a bound to success (implying a frontier and a tradeoff along that frontier of evidential/not)?

I don't think that changes your essential point though, that religion is a zero on the ratio. But I'm not sure that's so. Religions claim evidence, and used to claim it as matter-of-factly as a history textbook, before they learned the need to dodge. The big ones also base their case on the claimed evidence - pure gnostic mysticism has proven a memetic loser.