This will depend on each organization's goals and objectives for configuration management and asset management. If the organization wants to manage the CIs as assets also, then the models should have records created in asset tables. If not, you can prevent asset creation by updating the 'Asset tracking strategy' field of that model to "Don't create assets" (There is an option to create consumable assets also if needed. This is typically for models of low cost devices which are ordered in bulk).
As a general guideline, asset records should be created for the models for which the organization wants to manage one or more of the following aspects:
Financial information
Contract details
Inventory (ordering, receiving, stocks, disposal)
Warranty information
