A single powerful host can run a quite large business; you might put two identical instances of that host behind a loadbalancer to reduce downtime due failures

A single powerful host can run a quite large business; you might put two identical instances of that host behind a loadbalancer to reduce downtime due failures or upgrades/deployments, and for a single pair of hosts complex orchestration is IMHO overkill, you can just manually run the deploy on one host, wait for it to start working properly, and then upgrade the other.