SEO Expert for Website Migration

We're relaunching a WordPress site with a new theme on the same domain. The new build changed some URLs and consolidated a few pages. Our preferred approach is to align the new URLs to the existing structure wherever a page survives (so most pages need no redirect at all) and only redirect the handful of pages that no longer exist, but we're open to your read on the best strategy. The goal either way: get through the cutover without losing organic rankings, and set up to grow after. We want to move fast, with a tight turnaround once you're in. Live site and Cloudways staging shared once we hire. No outsourcing, no templated audits. What you'll deliver Live-site crawl and full URL inventory; GSC (16mo), GA4, and backlink pull to flag pages that hold equity URL alignment plan: match surviving pages to their existing URLs, plus a 301 map for orphaned/removed pages only (single-hop, no redirect-to-homepage) Port all titles, meta descriptions, H1s, alt text, schema, and internal links to the new build (currently missing) Migrate existing blog posts to the new site, URLs and content intact Pre-launch QA: fix canonicals (currently pointing at staging), confirm indexability, sitemap, Core Web Vitals, analytics/GSC carry-over Launch coordination plus a short post-launch check for 404s, broken redirects, and rankings vs. baseline, with a final report Must have Site migration track record, Screaming Frog, Ahrefs/Semrush, GSC + GA4, WordPress (RankMath/Yoast, redirects, custom post types/permalinks, schema). Local SEO a plus. To apply A migration or two you've handled and how it turned out (share before/after data if you have it) Quick note on how you'd approach this one, including whether you'd match URLs or redirect, and why Earliest start and how fast you can turn the core work around What's the #1 reason migrations lose rankings, and how do you prevent it?