Function take_relayer_diverse 

fn take_relayer_diverse(
    sorted: Vec<PathWithMetrics>,
    n: usize,
) -> Vec<PathWithMetrics>

Takes n candidates from sorted, preferring not-yet-represented first relayers.

Plain truncation keeps the n lowest-latency paths, which in a well-connected network are often the same few relayers reached by different routes; every downstream draw then inherits that concentration. Relative order is preserved, so each pass stays latency-ordered.