Summarized Alerts Based on Resource

Another way to accomplish coupling & correlation is to utilize Service Insights.  When you define a service you can group together multiple devices/instances and treat their metrics as part of a greater thing.  You then end up alerting from the Service you create, and that gets sent on to the next step of your operations (PagerDuty, ServiceNow, etc).

One note:  There are limitations on what things in the portal Services can be built on.  For example, the Websites monitoring is not supported at all by Service Insights.

Service Insights might be an extra sku, like Edwin AI, if you don't already have it in your portal.