If you are going to have more hosts, please note that it's not recommended to have more than 8 hosted-engine hosts. So if you'll still want to keep them all in the same cluster, some of them will be HE hosts and some not - this might be slightly confusing, depending on your use case. Thanks a lot for replying. I'm planning to just have 2 self-hosted hosts in the cluster01. I'll create a cluster02 and add the remaining regular hosts to it.
You can try searching the list archives for previous discussions about topology/architecture that people had over the years.
You might want to check also this somewhat-old but still mostly relevant doc, which is for RHV, but probably applies 99% to oVirt as well:
https://www.redhat.com/en/resources/best-practice-rhv-technology-detail
Good luck and best regards, I'll go through this doc and will also search the threads.