Look at Craft CMS multi site for a better implementation. It’s also multi-lingual, e.g. you can maintain Spanish and French translations for your global element

Look at Craft CMS multi site for a better implementation. It’s also multi-lingual, e.g. you can maintain Spanish and French translations for your global elements and then designate language for each of your sites and it’ll translate any shared content. However, for 300 sites, anything but a custom web app will get out of hand because that’s too many to manage in a UI that’s primarily meant for a handful of sites.