The proxy for content marketing in the following charts is "Attract", since content marketing is the top-of-the-funnel activity that attracts people to your business. "Convert" and "Close" refer to middle-of-the-funnel and bottom-of-the-funnel marketing activities, like email marketing, nurturing, sales enablement, marketing ops, conversion rate optimization, etc.
Your social media manager should also invest in growing your presence on social networks so that the content you share reaches an ever-growing audience. Consider the amplification of a piece of content shared on a Facebook page with 100,000 fans, versus 1,000 fans. The fans' networks work to help your content spread -- so the larger their networks, the better your content's distribution.
Your specific needs might vary -- for instance, perhaps you need subject matter expertise in your writers, or coding experience from your long-form content creators. Or perhaps your titles differ, and your "content creators" are actually "content strategists", or your "social media manager" is really a "specialist." Make edits as you see fit, but these frameworks should be helpful in getting you started if this is your first time hiring for any of these positions.