Can I install plain, single-cluster Fleet on a Harvester cluster (without Rancher). I would like to use it as an alternative to Terraform to bootstrap networking, images, configs and vms for the downstream clusters. And then bootstrap the Rancher cluster, that will become the management cluster.

it is via an external rancher, aim was not via the embedded rancher

Thank @great-bear-19718, the alternative I have now is to use Terraform or Bash Scripts to create the first Rancher on top of newly deployed Harvester. Nevertheless I've found this blog: https://ranchergovernment.com/blog/three-easy-mode-ways-of-installing-rancher-onto-harvester#e-Method-2 where the author uses embedded Rancher to run Bundle. I've found that is very easy to create: basic resources like this: https://github.com/harvester/harvester-fleet-examples/tree/main The only change is to pull it to fleet-local, not fleet-default. I wonder if that's not acceptable alternative to bootstrap the first Rancher instance, that will then take control over.