This is SB Nation, they have >100 separate sites (one per sports team in the leagues they cover, plus some extras), and they each have an "editor-in-chief" which is specific to that site and manages that community. It's not always their day job, as in this case it isn't.
Part time employees can work 5 hours a week. That’s got nothing to do with the employe vs contractor decide. Unless your ‘contractors’ are doing the same thing for multiple clients over the year, their probably employees.