Linkage is built from several dimensions; environment is only one
The factors that come up repeatedly in practitioner experience include: sign-in IP and its location, browser fingerprint, cookies and browser storage, payout accounts, shipping and return addresses, company and legal-entity details, and overlap in listings and copy.
Only the first two are observable from outside. Payout accounts, addresses and company details all live inside Amazon's systems, where no external tool can reach — which is why the verdict on this page is limited to the environment layer.