OSDOCS-5912: OSUS architecture recommendations

Author: skopacz1

modules/disconnected-osus-overview.adoc

@@ -11,4 +11,12 @@ The OpenShift Update Service (OSUS) provides update recommendations to {product-
 
 However, clusters in a disconnected environment cannot access these public APIs to retrieve update information. To have a similar update experience in a disconnected environment, you can install and configure the OpenShift Update Service locally so that it is available within the disconnected environment.
 
+A single OSUS instance is capable of serving recommendations to thousands of clusters.
+OSUS can be scaled horizontally to cater to more clusters by changing the replica value.
+So for most disconnected use cases, one OSUS instance is enough.
+For example, Red Hat hosts just one OSUS instance for the entire fleet of connected clusters.
+
+If you want to keep update recommendations separate in different environments, you can run one OSUS instance for each environment.
+For example, in a case where you have separate test and stage environments, you might not want a cluster in a stage environment to receive update recommendations to version A if that version has not been tested in the test environment yet.
+
 The following sections describe how to install a local OSUS instance and configure it to provide update recommendations to a cluster.