Standardized workstations and sacrificial components.
It helps to think of virtual desktops as single-use gloves. Do your job, walk away, and come back later to a fresh set of gloves.
Virtual desktops act as a sacrificial component. Any malware on a user's device or network smashes into the desktop, rather than the system the user is working on.
No. You will only need a different desktop for each concurrent user. So, if you have 10 users total, but in two shifts of 5 users each, you only need 5 desktops total.