Generate Azure Policy Compliance Alerts By Sending Custom Data to Log Analytics - Part 1

One thing to note is that this article describes how to use Azure Event Grid to send PolicyInsights data to a Log Analytics Workspace for the purpose of compliance alerting.  This solution using Event Grid does not require any kind of dedicated cluster for it to work.  The article you referenced describes how to send Event Hub data to Log Analytics, which may be different.  I am not very familiar with the solution in your referenced article so I cannot say why it has that requirement, but the solution we documented on this site does not have that requirement.

I would agree that having a more integrated solution that did not require additional deployments would be ideal and we have communicated that to the Azure Policy product group.  We are currently reviewing ways to streamline the deployments needed in this Event Grid solution, including automation and templates, so we may be posting a follow-up article on that topic so that would potentially streamline the deployment to be much easier than the step-by-step manual deployment described here.