Hello,
1. Please 1st check with your Esri account manager and review your license authorizations and options.
2. Next, determine what your user base is, what ArcGIS components they are using and their method of access to a license authorization. For example, if all your app users have Internet access all the time, hosting authorizations in AGOL makes sense. If, however, you have a mixture of user access such as Internet and organization network WAN users, hosting a portion of your license authorizations on premise makes sense. If deciding to host licenses on premise decide if you'll manage those in ArcGIS License Manager, ArcGIS Enterprise Portal or both. The combination of on premise and off premise license management does increase platform Admin overhead. However, making that investment will allow you to authorize components without consuming an AGOL seat just to license use another product like ArcGIS Desktop.
3. Our organization is large with a diverse user base need. We have a combination of license authorizations in AGOL, ArcGIS Enterprise Portal and two ArcGIS License managers (a primary and hot spare failover). This model supports our WAN only ArcGIS Desktop users, WAN/Internet users and our Internet (AGOL) users.
