Multiple WP installs & security

Hi All,

Any advise here would be much appreciated. The scenario I’m looking at is an on-prem hosting of multiple (possibly several dozen) WordPress instances each of which would be entirely separate sites with different administrators. Many of these admins would have limited technical skills and/or experience with WP upgrades, security etc. and could not necessarily be trusted to do their updates, manage their plugins, harden their installs… Multi-site not at option because of this.

Is there any way to achieve enough isolation from a security perspective on shared architecture (e.g one web front end server, one database server) or would the common ground of the web server user mean this could only be done with one set of servers per install? Thanks.