Whether or not you have asset records linked to inventory device records typically depends on what use cases/processes you are seeking to support. If you want to track the lifecycle and other business data about assets held by the organization, create asset records (and link them to relevant inventory device records). If you don't need to do that, you probably don't need to create asset records.

License consumption (of device-based licenses) is calculated base on inventory device records. Asset records are not required for managing software licenses.