Gilles, I'm not sure I understand your question, but to clarify a few things:
- Dynatrace supports the concept of environments and multiple environments created within a single Managed instance will reside in the same Managed cluster.
- Usage of Environments to separate Prod and Non_Prod is one way to separate them, however there are downsides of this approach. For example this forces a user to get out of one env and into another env just to look at data between the two environments.
- Have you looked at Management Zones? This might be a better solution for your use case. Certainly explore this powerful feature and use what's best for your needs.
You are correct, logout/login is not required with Environments. My point is that with Environments you have to switch between them to see data in more than one environment. But with Management Zones you can view data from more than one Management Zone on the same screen, assuming you have appropriate privileges to both Zones. Environments do not provide this flexibility.
Of course, you can't compare data between two tenants in Dynatrace itself. However, if you mix your non-prod and prod in one tenant, you should really consider using host groups. With management zones, you control mostly visibility and permissions.