Improve intro to manage devices

edge_manager/edge_mgr_manage.adoc

@@ -3,6 +3,13 @@
 
 After provisioning, you need to enroll your devices to manage them with the {rhem}.
 Device management includes organizing, monitoring, and updating the operating system and applications on your devices with the {rhem}.
+You can manage your devices individually or in a fleet.
+Managing your devices individually is advantageous in the following scenarios:
+
+* If your device configurations vary for each device.
+* If you need control over the order and timing of updates.
+
+//For managing your devices in a fleet, see xref:../[]
 
 For more information, read the following sections: