I set up two separate wp multisite installs in CPanel. When I tried to FTP to one of the sites to load some plugins & themes for the newer install, I noticed that all the plugins/themes I loaded in the first install were showing up in the WP content/plugins & WP content/themes folders of the second site. At that point, when I went into the 2nd site Admin area there were about 5 total plugins installed but there were 15 plugins showing up which were obviously from the first install.
In my feeble mind, it seems these two multisites should be run completely separately. There should be no "crossover". The subject matter is different enough that I don't want any overlap whatsoever.
Am I missing something here? Does WP use the same database for two completely separate multisite installs?