Parent-Child Company Hierarchy Mapping Tips with Clay for Salesforce

what is the best way to do parent-child company hierarchy mapping with Clay? Before I import new companies to Salesforce, I want to make sure that if they are tied to an existing hierarchy that they are added but linked to the correct account, and if they are potential duplicates to exclude. Some cases like Marriott are quite complex: many subsidiaries, sometimes multiple with the same domain but different names etc.