The diagnostic is simple: filter your GSC coverage report for Not Found URLs, cross-reference against your performance data, and look for anything with meaningful impressions. If a dead URL is sitting at position 8 or better, you have a rebuild candidate, not just a 404 to fix. On a lean static site like bree-sharp.com, where every ranking signal matters and there's no domain authority cushion to lean on, capturing existing equity before building new is the right sequencing.