AFAIK you cannot set certain hosts to present to have quorum. The majority will have the quorum. Because of this, it is also recommended to have an odd number of hosts in a cluster so that there cannot be one half of the cluster online. To avoid this you can add a small external "device" that adds one more vote to the cluster to have an odd number of votes. See https://pve.proxmox.com/pve-docs/pve-admin-guide.html#_corosync_external_vote_support