"My hosting company is constantly snapping daily copies of my web hosting database and weekly copies of my files."
Then moodledata/filedir should be included in weekly copies of files ... that's where you say auto course backups are set to go.
Don't work for your provider ... sounds good ... but, depending upon your paranoid level, might consider downloading the .mbz files to store locally ... off server, off remote systems. At least, when there has been a major assignment students have submitted - a backup that I can download.
Do know that .mbz files by themselves are not usable in a normal sense ... they are special backups and do require a Moodle of same or higher version of Moodle to restore ... unless you know some 'geeky stuff'.
The timing of DB and files ... if you have a busy site and students are using assignments to upload files, the DB and moodledata/filedir/ should be done on same day. Otherwise your DB .. which has meta data pointing to files in moodledata/filedir/ is more up to date than the weekly backup of moodledata/filedir/
But do understand why provider doesn't do that as moodledata/filedir could be huge.
So ... like I said ... depends on your paranoia level!
Will say I've never regretted taking the time to archive course backups off servers, however.