Creative Cloud individual membership works on one membership per Adobe ID.
Multiple memberships require multiple Adobe IDs.
To get what you want, you need Adobe Creative Cloud for Teams
http://www.adobe.com/products/creativecloud/teams.html
http://www.adobe.com/au/products/creativecloud/faq.html#ccm-teams
You'll have to weigh up the cost vs convenience of the individual vs team membership.