In ServiceNow, controlling source precedence when multiple authorized data sources update the same CI attributes is a core responsibility of Identification and Reconciliation Engine (IRE) governance.
The correct and supported method is to assign priority to each data source in reconciliation rules.
Reconciliation rules determine which source wins when multiple sources attempt to update the same attribute on a CI. By defining source precedence, the Configuration Manager ensures that the most authoritative system of record (for example, Discovery over manual imports, or HR systems over spreadsheets) consistently controls specific attributes or classes.