Function stand_in_reliability 

fn stand_in_reliability(seed: u64, index: usize) -> f64

A pseudo-random stand-in reliability, uniform over [0, 2^31).

The range matches C’s RAND_MAX, which is what the reference draws from. Real reliabilities are bounded by 13·(2π)² ≈ 513, so these effectively always sort last — exactly as in the reference, including its vanishingly rare exceptions.