You'll need a QDevice to keep consensus. That wiki article will cover how to set it up and some drawbacks to QDevices. You should be able to run it on a low-power device like a Pi to keep the cluster going.

If you are not using any HA feature and only put servers into the same cluster for ease of management.

You could use the same command but with a value of 1.

The reason quorum exist is to prevent any server to arbitrarily failover VMs when it believes the other node(s) is down and create a split brain situation.

But if that risk does not exist to begin with, so do the quorum.

Please do add a tag to your post as stated on the sublemmy sidebar! Thank you. :)

AFAIK forcing it to a lower number is fine if you're not doing HA. I remember reading something along those lines on a forum, but I could be remembering wrong.

If you're not using Ceph or HA, then I don't think there would be any negative effects from not having all the servers in the cluster ready.