It doesn’t quite say that, but I think the meaning is essentially the same: “Don’t choose a name after a project unique to that machine.” - RFC 1178
For my homelab, I think that’s fine to do. I’m unlikely to have multiple Plex servers locally, for example, and if so, numerically naming them is fine - I provision with Ansible, and if I’m at the point where I’m having sequentially numbered hosts, they’ll be configured as cattle anyway. Also, having the names reflect the services a host provides makes it easier to match in my playbooks.
I think it’s a better scheme than turning to mythology, fiction, or animal species, which oddly enough RFC 1178 does encourage you to do.