Hi Sven,
As of now, an error message will be displayed if the selected Software Name & Product Name are different. We will hide the Product Name field in future for the Software products.
Instead of adding the Office 365 ProPlus, Office 365 Enterprise E1, Office 365 Enterprise E3, Office 365 Enterprise E5 as separate products in the application, you can add them as a license types or License options and manage them. You will be able to create license types by going to Setup-->Customization-->Asset Management-->Software License types. You can create different types of licenses based on Installation's allowed as well.
Please refer to the below link for more details,
Please get back to us for further clarifications.
Thanks & Regards,
Ram
ServiceDesk Plus OnDemand Support